Merge branch 'cc/apply-introduce-state'

The "git apply" standalone program is being libified; this is the
first step to move many state variables into a structure that can
be explicitly (re)initialized to make the machinery callable more
than once.

The next step that moves some remaining state variables into the
structure and turns die()s into an error return that propagates up
to the caller is not queued yet but in flight.  It would be good to
review the above first and give the remainder of the series a solid
base to build on.

* cc/apply-introduce-state: (50 commits)
  builtin/apply: remove misleading comment on lock_file field
  builtin/apply: move 'newfd' global into 'struct apply_state'
  builtin/apply: add 'lock_file' pointer into 'struct apply_state'
  builtin/apply: move applying patches into apply_all_patches()
  builtin/apply: move 'state' check into check_apply_state()
  builtin/apply: move 'symlink_changes' global into 'struct apply_state'
  builtin/apply: move 'fn_table' global into 'struct apply_state'
  builtin/apply: move 'state_linenr' global into 'struct apply_state'
  builtin/apply: move 'max_change' and 'max_len' into 'struct apply_state'
  builtin/apply: move 'ws_ignore_action' into 'struct apply_state'
  builtin/apply: move 'ws_error_action' into 'struct apply_state'
  builtin/apply: move 'applied_after_fixing_ws' into 'struct apply_state'
  builtin/apply: move 'squelch_whitespace_errors' into 'struct apply_state'
  builtin/apply: remove whitespace_option arg from set_default_whitespace_mode()
  builtin/apply: move 'whitespace_option' into 'struct apply_state'
  builtin/apply: move 'whitespace_error' global into 'struct apply_state'
  builtin/apply: move 'root' global into 'struct apply_state'
  builtin/apply: move 'p_value_known' global into 'struct apply_state'
  builtin/apply: move 'p_value' global into 'struct apply_state'
  builtin/apply: move 'has_include' global into 'struct apply_state'
  ...

1 files changed, 820 insertions, 609 deletions

diff --git a/builtin/apply.c b/builtin/apply.c
index c770d7d3d9..ecb7f1b258 100644
--- a/builtin/apply.c
+++ b/builtin/apply.c
@@ -21,132 +21,161 @@
 #include "ll-merge.h"
 #include "rerere.h"
 
-/*
- *  --check turns on checking that the working tree matches the
- *    files that are being modified, but doesn't apply the patch
- *  --stat does just a diffstat, and doesn't actually apply
- *  --numstat does numeric diffstat, and doesn't actually apply
- *  --index-info shows the old and new index info for paths if available.
- *  --index updates the cache as well.
- *  --cached updates only the cache without ever touching the working tree.
- */
-static const char *prefix;
-static int prefix_length = -1;
-static int newfd = -1;
-
-static int unidiff_zero;
-static int p_value = 1;
-static int p_value_known;
-static int check_index;
-static int update_index;
-static int cached;
-static int diffstat;
-static int numstat;
-static int summary;
-static int check;
-static int apply = 1;
-static int apply_in_reverse;
-static int apply_with_reject;
-static int apply_verbosely;
-static int allow_overlap;
-static int no_add;
-static int threeway;
-static int unsafe_paths;
-static const char *fake_ancestor;
-static int line_termination = '\n';
-static unsigned int p_context = UINT_MAX;
-static const char * const apply_usage[] = {
-	N_("git apply [<options>] [<patch>...]"),
-	NULL
-};
-
-static enum ws_error_action {
+enum ws_error_action {
 	nowarn_ws_error,
 	warn_on_ws_error,
 	die_on_ws_error,
 	correct_ws_error
-} ws_error_action = warn_on_ws_error;
-static int whitespace_error;
-static int squelch_whitespace_errors = 5;
-static int applied_after_fixing_ws;
+};
+
 
-static enum ws_ignore {
+enum ws_ignore {
 	ignore_ws_none,
 	ignore_ws_change
-} ws_ignore_action = ignore_ws_none;
+};
+
+/*
+ * We need to keep track of how symlinks in the preimage are
+ * manipulated by the patches.  A patch to add a/b/c where a/b
+ * is a symlink should not be allowed to affect the directory
+ * the symlink points at, but if the same patch removes a/b,
+ * it is perfectly fine, as the patch removes a/b to make room
+ * to create a directory a/b so that a/b/c can be created.
+ *
+ * See also "struct string_list symlink_changes" in "struct
+ * apply_state".
+ */
+#define SYMLINK_GOES_AWAY 01
+#define SYMLINK_IN_RESULT 02
 
+struct apply_state {
+	const char *prefix;
+	int prefix_length;
+
+	/* These are lock_file related */
+	struct lock_file *lock_file;
+	int newfd;
+
+	/* These control what gets looked at and modified */
+	int apply; /* this is not a dry-run */
+	int cached; /* apply to the index only */
+	int check; /* preimage must match working tree, don't actually apply */
+	int check_index; /* preimage must match the indexed version */
+	int update_index; /* check_index && apply */
+
+	/* These control cosmetic aspect of the output */
+	int diffstat; /* just show a diffstat, and don't actually apply */
+	int numstat; /* just show a numeric diffstat, and don't actually apply */
+	int summary; /* just report creation, deletion, etc, and don't actually apply */
+
+	/* These boolean parameters control how the apply is done */
+	int allow_overlap;
+	int apply_in_reverse;
+	int apply_with_reject;
+	int apply_verbosely;
+	int no_add;
+	int threeway;
+	int unidiff_zero;
+	int unsafe_paths;
+
+	/* Other non boolean parameters */
+	const char *fake_ancestor;
+	const char *patch_input_file;
+	int line_termination;
+	struct strbuf root;
+	int p_value;
+	int p_value_known;
+	unsigned int p_context;
+
+	/* Exclude and include path parameters */
+	struct string_list limit_by_name;
+	int has_include;
+
+	/* Various "current state" */
+	int linenr; /* current line number */
+	struct string_list symlink_changes; /* we have to track symlinks */
 
-static const char *patch_input_file;
-static struct strbuf root = STRBUF_INIT;
-static int read_stdin = 1;
-static int options;
+	/*
+	 * For "diff-stat" like behaviour, we keep track of the biggest change
+	 * we've seen, and the longest filename. That allows us to do simple
+	 * scaling.
+	 */
+	int max_change;
+	int max_len;
 
-static void parse_whitespace_option(const char *option)
+	/*
+	 * Records filenames that have been touched, in order to handle
+	 * the case where more than one patches touch the same file.
+	 */
+	struct string_list fn_table;
+
+	/* These control whitespace errors */
+	enum ws_error_action ws_error_action;
+	enum ws_ignore ws_ignore_action;
+	const char *whitespace_option;
+	int whitespace_error;
+	int squelch_whitespace_errors;
+	int applied_after_fixing_ws;
+};
+
+static const char * const apply_usage[] = {
+	N_("git apply [<options>] [<patch>...]"),
+	NULL
+};
+
+static void parse_whitespace_option(struct apply_state *state, const char *option)
 {
 	if (!option) {
-		ws_error_action = warn_on_ws_error;
+		state->ws_error_action = warn_on_ws_error;
 		return;
 	}
 	if (!strcmp(option, "warn")) {
-		ws_error_action = warn_on_ws_error;
+		state->ws_error_action = warn_on_ws_error;
 		return;
 	}
 	if (!strcmp(option, "nowarn")) {
-		ws_error_action = nowarn_ws_error;
+		state->ws_error_action = nowarn_ws_error;
 		return;
 	}
 	if (!strcmp(option, "error")) {
-		ws_error_action = die_on_ws_error;
+		state->ws_error_action = die_on_ws_error;
 		return;
 	}
 	if (!strcmp(option, "error-all")) {
-		ws_error_action = die_on_ws_error;
-		squelch_whitespace_errors = 0;
+		state->ws_error_action = die_on_ws_error;
+		state->squelch_whitespace_errors = 0;
 		return;
 	}
 	if (!strcmp(option, "strip") || !strcmp(option, "fix")) {
-		ws_error_action = correct_ws_error;
+		state->ws_error_action = correct_ws_error;
 		return;
 	}
 	die(_("unrecognized whitespace option '%s'"), option);
 }
 
-static void parse_ignorewhitespace_option(const char *option)
+static void parse_ignorewhitespace_option(struct apply_state *state,
+					  const char *option)
 {
 	if (!option || !strcmp(option, "no") ||
 	    !strcmp(option, "false") || !strcmp(option, "never") ||
 	    !strcmp(option, "none")) {
-		ws_ignore_action = ignore_ws_none;
+		state->ws_ignore_action = ignore_ws_none;
 		return;
 	}
 	if (!strcmp(option, "change")) {
-		ws_ignore_action = ignore_ws_change;
+		state->ws_ignore_action = ignore_ws_change;
 		return;
 	}
 	die(_("unrecognized whitespace ignore option '%s'"), option);
 }
 
-static void set_default_whitespace_mode(const char *whitespace_option)
+static void set_default_whitespace_mode(struct apply_state *state)
 {
-	if (!whitespace_option && !apply_default_whitespace)
-		ws_error_action = (apply ? warn_on_ws_error : nowarn_ws_error);
+	if (!state->whitespace_option && !apply_default_whitespace)
+		state->ws_error_action = (state->apply ? warn_on_ws_error : nowarn_ws_error);
 }
 
 /*
- * For "diff-stat" like behaviour, we keep track of the biggest change
- * we've seen, and the longest filename. That allows us to do simple
- * scaling.
- */
-static int max_change, max_len;
-
-/*
- * Various "current state", notably line numbers and what
- * file (and how) we're patching right now.. The "is_xxxx"
- * things are flags, where -1 means "don't know yet".
- */
-static int linenr = 1;
-
-/*
  * This represents one "hunk" from a patch, starting with
  * "@@ -oldpos,oldlines +newpos,newlines @@" marker.  The
  * patch text is pointed at by patch, and its byte length
@@ -265,13 +294,6 @@ struct image {
 	struct line *line;
 };
 
-/*
- * Records filenames that have been touched, in order to handle
- * the case where more than one patches touch the same file.
- */
-
-static struct string_list fn_table;
-
 static uint32_t hash_line(const char *cp, size_t len)
 {
 	size_t i;
@@ -469,7 +491,10 @@ static char *squash_slash(char *name)
 	return name;
 }
 
-static char *find_name_gnu(const char *line, const char *def, int p_value)
+static char *find_name_gnu(struct apply_state *state,
+			   const char *line,
+			   const char *def,
+			   int p_value)
 {
 	struct strbuf name = STRBUF_INIT;
 	char *cp;
@@ -493,8 +518,8 @@ static char *find_name_gnu(const char *line, const char *def, int p_value)
 	}
 
 	strbuf_remove(&name, 0, cp - name.buf);
-	if (root.len)
-		strbuf_insert(&name, 0, root.buf, root.len);
+	if (state->root.len)
+		strbuf_insert(&name, 0, state->root.buf, state->root.len);
 	return squash_slash(strbuf_detach(&name, NULL));
 }
 
@@ -657,8 +682,12 @@ static size_t diff_timestamp_len(const char *line, size_t len)
 	return line + len - end;
 }
 
-static char *find_name_common(const char *line, const char *def,
-			      int p_value, const char *end, int terminate)
+static char *find_name_common(struct apply_state *state,
+			      const char *line,
+			      const char *def,
+			      int p_value,
+			      const char *end,
+			      int terminate)
 {
 	int len;
 	const char *start = NULL;
@@ -696,32 +725,39 @@ static char *find_name_common(const char *line, const char *def,
 			return squash_slash(xstrdup(def));
 	}
 
-	if (root.len) {
-		char *ret = xstrfmt("%s%.*s", root.buf, len, start);
+	if (state->root.len) {
+		char *ret = xstrfmt("%s%.*s", state->root.buf, len, start);
 		return squash_slash(ret);
 	}
 
 	return squash_slash(xmemdupz(start, len));
 }
 
-static char *find_name(const char *line, char *def, int p_value, int terminate)
+static char *find_name(struct apply_state *state,
+		       const char *line,
+		       char *def,
+		       int p_value,
+		       int terminate)
 {
 	if (*line == '"') {
-		char *name = find_name_gnu(line, def, p_value);
+		char *name = find_name_gnu(state, line, def, p_value);
 		if (name)
 			return name;
 	}
 
-	return find_name_common(line, def, p_value, NULL, terminate);
+	return find_name_common(state, line, def, p_value, NULL, terminate);
 }
 
-static char *find_name_traditional(const char *line, char *def, int p_value)
+static char *find_name_traditional(struct apply_state *state,
+				   const char *line,
+				   char *def,
+				   int p_value)
 {
 	size_t len;
 	size_t date_len;
 
 	if (*line == '"') {
-		char *name = find_name_gnu(line, def, p_value);
+		char *name = find_name_gnu(state, line, def, p_value);
 		if (name)
 			return name;
 	}
@@ -729,10 +765,10 @@ static char *find_name_traditional(const char *line, char *def, int p_value)
 	len = strchrnul(line, '\n') - line;
 	date_len = diff_timestamp_len(line, len);
 	if (!date_len)
-		return find_name_common(line, def, p_value, NULL, TERM_TAB);
+		return find_name_common(state, line, def, p_value, NULL, TERM_TAB);
 	len -= date_len;
 
-	return find_name_common(line, def, p_value, line + len, 0);
+	return find_name_common(state, line, def, p_value, line + len, 0);
 }
 
 static int count_slashes(const char *cp)
@@ -750,30 +786,30 @@ static int count_slashes(const char *cp)
  * Given the string after "--- " or "+++ ", guess the appropriate
  * p_value for the given patch.
  */
-static int guess_p_value(const char *nameline)
+static int guess_p_value(struct apply_state *state, const char *nameline)
 {
 	char *name, *cp;
 	int val = -1;
 
 	if (is_dev_null(nameline))
 		return -1;
-	name = find_name_traditional(nameline, NULL, 0);
+	name = find_name_traditional(state, nameline, NULL, 0);
 	if (!name)
 		return -1;
 	cp = strchr(name, '/');
 	if (!cp)
 		val = 0;
-	else if (prefix) {
+	else if (state->prefix) {
 		/*
 		 * Does it begin with "a/$our-prefix" and such?  Then this is
 		 * very likely to apply to our directory.
 		 */
-		if (!strncmp(name, prefix, prefix_length))
-			val = count_slashes(prefix);
+		if (!strncmp(name, state->prefix, state->prefix_length))
+			val = count_slashes(state->prefix);
 		else {
 			cp++;
-			if (!strncmp(cp, prefix, prefix_length))
-				val = count_slashes(prefix) + 1;
+			if (!strncmp(cp, state->prefix, state->prefix_length))
+				val = count_slashes(state->prefix) + 1;
 		}
 	}
 	free(name);
@@ -860,36 +896,39 @@ static int has_epoch_timestamp(const char *nameline)
  * files, we can happily check the index for a match, but for creating a
  * new file we should try to match whatever "patch" does. I have no idea.
  */
-static void parse_traditional_patch(const char *first, const char *second, struct patch *patch)
+static void parse_traditional_patch(struct apply_state *state,
+				    const char *first,
+				    const char *second,
+				    struct patch *patch)
 {
 	char *name;
 
 	first += 4;	/* skip "--- " */
 	second += 4;	/* skip "+++ " */
-	if (!p_value_known) {
+	if (!state->p_value_known) {
 		int p, q;
-		p = guess_p_value(first);
-		q = guess_p_value(second);
+		p = guess_p_value(state, first);
+		q = guess_p_value(state, second);
 		if (p < 0) p = q;
 		if (0 <= p && p == q) {
-			p_value = p;
-			p_value_known = 1;
+			state->p_value = p;
+			state->p_value_known = 1;
 		}
 	}
 	if (is_dev_null(first)) {
 		patch->is_new = 1;
 		patch->is_delete = 0;
-		name = find_name_traditional(second, NULL, p_value);
+		name = find_name_traditional(state, second, NULL, state->p_value);
 		patch->new_name = name;
 	} else if (is_dev_null(second)) {
 		patch->is_new = 0;
 		patch->is_delete = 1;
-		name = find_name_traditional(first, NULL, p_value);
+		name = find_name_traditional(state, first, NULL, state->p_value);
 		patch->old_name = name;
 	} else {
 		char *first_name;
-		first_name = find_name_traditional(first, NULL, p_value);
-		name = find_name_traditional(second, first_name, p_value);
+		first_name = find_name_traditional(state, first, NULL, state->p_value);
+		name = find_name_traditional(state, second, first_name, state->p_value);
 		free(first_name);
 		if (has_epoch_timestamp(first)) {
 			patch->is_new = 1;
@@ -905,10 +944,12 @@ static void parse_traditional_patch(const char *first, const char *second, struc
 		}
 	}
 	if (!name)
-		die(_("unable to find filename in patch at line %d"), linenr);
+		die(_("unable to find filename in patch at line %d"), state->linenr);
 }
 
-static int gitdiff_hdrend(const char *line, struct patch *patch)
+static int gitdiff_hdrend(struct apply_state *state,
+			  const char *line,
+			  struct patch *patch)
 {
 	return -1;
 }
@@ -925,107 +966,135 @@ static int gitdiff_hdrend(const char *line, struct patch *patch)
 #define DIFF_OLD_NAME 0
 #define DIFF_NEW_NAME 1
 
-static char *gitdiff_verify_name(const char *line, int isnull, char *orig_name, int side)
+static void gitdiff_verify_name(struct apply_state *state,
+				const char *line,
+				int isnull,
+				char **name,
+				int side)
 {
-	if (!orig_name && !isnull)
-		return find_name(line, NULL, p_value, TERM_TAB);
+	if (!*name && !isnull) {
+		*name = find_name(state, line, NULL, state->p_value, TERM_TAB);
+		return;
+	}
 
-	if (orig_name) {
-		int len = strlen(orig_name);
+	if (*name) {
+		int len = strlen(*name);
 		char *another;
 		if (isnull)
 			die(_("git apply: bad git-diff - expected /dev/null, got %s on line %d"),
-			    orig_name, linenr);
-		another = find_name(line, NULL, p_value, TERM_TAB);
-		if (!another || memcmp(another, orig_name, len + 1))
+			    *name, state->linenr);
+		another = find_name(state, line, NULL, state->p_value, TERM_TAB);
+		if (!another || memcmp(another, *name, len + 1))
 			die((side == DIFF_NEW_NAME) ?
 			    _("git apply: bad git-diff - inconsistent new filename on line %d") :
-			    _("git apply: bad git-diff - inconsistent old filename on line %d"), linenr);
+			    _("git apply: bad git-diff - inconsistent old filename on line %d"), state->linenr);
 		free(another);
-		return orig_name;
 	} else {
 		/* expect "/dev/null" */
 		if (memcmp("/dev/null", line, 9) || line[9] != '\n')
-			die(_("git apply: bad git-diff - expected /dev/null on line %d"), linenr);
-		return NULL;
+			die(_("git apply: bad git-diff - expected /dev/null on line %d"), state->linenr);
 	}
 }
 
-static int gitdiff_oldname(const char *line, struct patch *patch)
+static int gitdiff_oldname(struct apply_state *state,
+			   const char *line,
+			   struct patch *patch)
 {
-	patch->old_name = gitdiff_verify_name(line, patch->is_new, patch->old_name,
-					      DIFF_OLD_NAME);
+	gitdiff_verify_name(state, line,
+			    patch->is_new, &patch->old_name,
+			    DIFF_OLD_NAME);
 	return 0;
 }
 
-static int gitdiff_newname(const char *line, struct patch *patch)
+static int gitdiff_newname(struct apply_state *state,
+			   const char *line,
+			   struct patch *patch)
 {
-	patch->new_name = gitdiff_verify_name(line, patch->is_delete, patch->new_name,
-					      DIFF_NEW_NAME);
+	gitdiff_verify_name(state, line,
+			    patch->is_delete, &patch->new_name,
+			    DIFF_NEW_NAME);
 	return 0;
 }
 
-static int gitdiff_oldmode(const char *line, struct patch *patch)
+static int gitdiff_oldmode(struct apply_state *state,
+			   const char *line,
+			   struct patch *patch)
 {
 	patch->old_mode = strtoul(line, NULL, 8);
 	return 0;
 }
 
-static int gitdiff_newmode(const char *line, struct patch *patch)
+static int gitdiff_newmode(struct apply_state *state,
+			   const char *line,
+			   struct patch *patch)
 {
 	patch->new_mode = strtoul(line, NULL, 8);
 	return 0;
 }
 
-static int gitdiff_delete(const char *line, struct patch *patch)
+static int gitdiff_delete(struct apply_state *state,
+			  const char *line,
+			  struct patch *patch)
 {
 	patch->is_delete = 1;
 	free(patch->old_name);
 	patch->old_name = xstrdup_or_null(patch->def_name);
-	return gitdiff_oldmode(line, patch);
+	return gitdiff_oldmode(state, line, patch);
 }
 
-static int gitdiff_newfile(const char *line, struct patch *patch)
+static int gitdiff_newfile(struct apply_state *state,
+			   const char *line,
+			   struct patch *patch)
 {
 	patch->is_new = 1;
 	free(patch->new_name);
 	patch->new_name = xstrdup_or_null(patch->def_name);
-	return gitdiff_newmode(line, patch);
+	return gitdiff_newmode(state, line, patch);
 }
 
-static int gitdiff_copysrc(const char *line, struct patch *patch)
+static int gitdiff_copysrc(struct apply_state *state,
+			   const char *line,
+			   struct patch *patch)
 {
 	patch->is_copy = 1;
 	free(patch->old_name);
-	patch->old_name = find_name(line, NULL, p_value ? p_value - 1 : 0, 0);
+	patch->old_name = find_name(state, line, NULL, state->p_value ? state->p_value - 1 : 0, 0);
 	return 0;
 }
 
-static int gitdiff_copydst(const char *line, struct patch *patch)
+static int gitdiff_copydst(struct apply_state *state,
+			   const char *line,
+			   struct patch *patch)
 {
 	patch->is_copy = 1;
 	free(patch->new_name);
-	patch->new_name = find_name(line, NULL, p_value ? p_value - 1 : 0, 0);
+	patch->new_name = find_name(state, line, NULL, state->p_value ? state->p_value - 1 : 0, 0);
 	return 0;
 }
 
-static int gitdiff_renamesrc(const char *line, struct patch *patch)
+static int gitdiff_renamesrc(struct apply_state *state,
+			     const char *line,
+			     struct patch *patch)
 {
 	patch->is_rename = 1;
 	free(patch->old_name);
-	patch->old_name = find_name(line, NULL, p_value ? p_value - 1 : 0, 0);
+	patch->old_name = find_name(state, line, NULL, state->p_value ? state->p_value - 1 : 0, 0);
 	return 0;
 }
 
-static int gitdiff_renamedst(const char *line, struct patch *patch)
+static int gitdiff_renamedst(struct apply_state *state,
+			     const char *line,
+			     struct patch *patch)
 {
 	patch->is_rename = 1;
 	free(patch->new_name);
-	patch->new_name = find_name(line, NULL, p_value ? p_value - 1 : 0, 0);
+	patch->new_name = find_name(state, line, NULL, state->p_value ? state->p_value - 1 : 0, 0);
 	return 0;
 }
 
-static int gitdiff_similarity(const char *line, struct patch *patch)
+static int gitdiff_similarity(struct apply_state *state,
+			      const char *line,
+			      struct patch *patch)
 {
 	unsigned long val = strtoul(line, NULL, 10);
 	if (val <= 100)
@@ -1033,7 +1102,9 @@ static int gitdiff_similarity(const char *line, struct patch *patch)
 	return 0;
 }
 
-static int gitdiff_dissimilarity(const char *line, struct patch *patch)
+static int gitdiff_dissimilarity(struct apply_state *state,
+				 const char *line,
+				 struct patch *patch)
 {
 	unsigned long val = strtoul(line, NULL, 10);
 	if (val <= 100)
@@ -1041,7 +1112,9 @@ static int gitdiff_dissimilarity(const char *line, struct patch *patch)
 	return 0;
 }
 
-static int gitdiff_index(const char *line, struct patch *patch)
+static int gitdiff_index(struct apply_state *state,
+			 const char *line,
+			 struct patch *patch)
 {
 	/*
 	 * index line is N hexadecimal, "..", N hexadecimal,
@@ -1078,7 +1151,9 @@ static int gitdiff_index(const char *line, struct patch *patch)
  * This is normal for a diff that doesn't change anything: we'll fall through
  * into the next diff. Tell the parser to break out.
  */
-static int gitdiff_unrecognized(const char *line, struct patch *patch)
+static int gitdiff_unrecognized(struct apply_state *state,
+				const char *line,
+				struct patch *patch)
 {
 	return -1;
 }
@@ -1087,15 +1162,17 @@ static int gitdiff_unrecognized(const char *line, struct patch *patch)
  * Skip p_value leading components from "line"; as we do not accept
  * absolute paths, return NULL in that case.
  */
-static const char *skip_tree_prefix(const char *line, int llen)
+static const char *skip_tree_prefix(struct apply_state *state,
+				    const char *line,
+				    int llen)
 {
 	int nslash;
 	int i;
 
-	if (!p_value)
+	if (!state->p_value)
 		return (llen && line[0] == '/') ? NULL : line;
 
-	nslash = p_value;
+	nslash = state->p_value;
 	for (i = 0; i < llen; i++) {
 		int ch = line[i];
 		if (ch == '/' && --nslash <= 0)
@@ -1112,7 +1189,9 @@ static const char *skip_tree_prefix(const char *line, int llen)
  * creation or deletion of an empty file.  In any of these cases,
  * both sides are the same name under a/ and b/ respectively.
  */
-static char *git_header_name(const char *line, int llen)
+static char *git_header_name(struct apply_state *state,
+			     const char *line,
+			     int llen)
 {
 	const char *name;
 	const char *second = NULL;
@@ -1130,7 +1209,7 @@ static char *git_header_name(const char *line, int llen)
 			goto free_and_fail1;
 
 		/* strip the a/b prefix including trailing slash */
-		cp = skip_tree_prefix(first.buf, first.len);
+		cp = skip_tree_prefix(state, first.buf, first.len);
 		if (!cp)
 			goto free_and_fail1;
 		strbuf_remove(&first, 0, cp - first.buf);
@@ -1147,7 +1226,7 @@ static char *git_header_name(const char *line, int llen)
 		if (*second == '"') {
 			if (unquote_c_style(&sp, second, NULL))
 				goto free_and_fail1;
-			cp = skip_tree_prefix(sp.buf, sp.len);
+			cp = skip_tree_prefix(state, sp.buf, sp.len);
 			if (!cp)
 				goto free_and_fail1;
 			/* They must match, otherwise ignore */
@@ -1158,7 +1237,7 @@ static char *git_header_name(const char *line, int llen)
 		}
 
 		/* unquoted second */
-		cp = skip_tree_prefix(second, line + llen - second);
+		cp = skip_tree_prefix(state, second, line + llen - second);
 		if (!cp)
 			goto free_and_fail1;
 		if (line + llen - cp != first.len ||
@@ -1173,7 +1252,7 @@ static char *git_header_name(const char *line, int llen)
 	}
 
 	/* unquoted first name */
-	name = skip_tree_prefix(line, llen);
+	name = skip_tree_prefix(state, line, llen);
 	if (!name)
 		return NULL;
 
@@ -1189,7 +1268,7 @@ static char *git_header_name(const char *line, int llen)
 			if (unquote_c_style(&sp, second, NULL))
 				goto free_and_fail2;
 
-			np = skip_tree_prefix(sp.buf, sp.len);
+			np = skip_tree_prefix(state, sp.buf, sp.len);
 			if (!np)
 				goto free_and_fail2;
 
@@ -1233,7 +1312,7 @@ static char *git_header_name(const char *line, int llen)
 			 */
 			if (!name[len + 1])
 				return NULL; /* no postimage name */
-			second = skip_tree_prefix(name + len + 1,
+			second = skip_tree_prefix(state, name + len + 1,
 						  line_len - (len + 1));
 			if (!second)
 				return NULL;
@@ -1249,7 +1328,11 @@ static char *git_header_name(const char *line, int llen)
 }
 
 /* Verify that we recognize the lines following a git header */
-static int parse_git_header(const char *line, int len, unsigned int size, struct patch *patch)
+static int parse_git_header(struct apply_state *state,
+			    const char *line,
+			    int len,
+			    unsigned int size,
+			    struct patch *patch)
 {
 	unsigned long offset;
 
@@ -1263,20 +1346,20 @@ static int parse_git_header(const char *line, int len, unsigned int size, struct
 	 * or removing or adding empty files), so we get
 	 * the default name from the header.
 	 */
-	patch->def_name = git_header_name(line, len);
-	if (patch->def_name && root.len) {
-		char *s = xstrfmt("%s%s", root.buf, patch->def_name);
+	patch->def_name = git_header_name(state, line, len);
+	if (patch->def_name && state->root.len) {
+		char *s = xstrfmt("%s%s", state->root.buf, patch->def_name);
 		free(patch->def_name);
 		patch->def_name = s;
 	}
 
 	line += len;
 	size -= len;
-	linenr++;
-	for (offset = len ; size > 0 ; offset += len, size -= len, line += len, linenr++) {
+	state->linenr++;
+	for (offset = len ; size > 0 ; offset += len, size -= len, line += len, state->linenr++) {
 		static const struct opentry {
 			const char *str;
-			int (*fn)(const char *, struct patch *);
+			int (*fn)(struct apply_state *, const char *, struct patch *);
 		} optable[] = {
 			{ "@@ -", gitdiff_hdrend },
 			{ "--- ", gitdiff_oldname },
@@ -1306,7 +1389,7 @@ static int parse_git_header(const char *line, int len, unsigned int size, struct
 			int oplen = strlen(p->str);
 			if (len < oplen || memcmp(p->str, line, oplen))
 				continue;
-			if (p->fn(line + oplen, patch) < 0)
+			if (p->fn(state, line + oplen, patch) < 0)
 				return offset;
 			break;
 		}
@@ -1431,7 +1514,11 @@ static int parse_fragment_header(const char *line, int len, struct fragment *fra
 	return offset;
 }
 
-static int find_header(const char *line, unsigned long size, int *hdrsize, struct patch *patch)
+static int find_header(struct apply_state *state,
+		       const char *line,
+		       unsigned long size,
+		       int *hdrsize,
+		       struct patch *patch)
 {
 	unsigned long offset, len;
 
@@ -1440,7 +1527,7 @@ static int find_header(const char *line, unsigned long size, int *hdrsize, struc
 	patch->is_new = patch->is_delete = -1;
 	patch->old_mode = patch->new_mode = 0;
 	patch->old_name = patch->new_name = NULL;
-	for (offset = 0; size > 0; offset += len, size -= len, line += len, linenr++) {
+	for (offset = 0; size > 0; offset += len, size -= len, line += len, state->linenr++) {
 		unsigned long nextlen;
 
 		len = linelen(line, size);
@@ -1461,7 +1548,7 @@ static int find_header(const char *line, unsigned long size, int *hdrsize, struc
 			if (parse_fragment_header(line, len, &dummy) < 0)
 				continue;
 			die(_("patch fragment without header at line %d: %.*s"),
-			    linenr, (int)len-1, line);
+			    state->linenr, (int)len-1, line);
 		}
 
 		if (size < len + 6)
@@ -1472,7 +1559,7 @@ static int find_header(const char *line, unsigned long size, int *hdrsize, struc
 		 * or mode change, so we handle that specially
 		 */
 		if (!memcmp("diff --git ", line, 11)) {
-			int git_hdr_len = parse_git_header(line, len, size, patch);
+			int git_hdr_len = parse_git_header(state, line, len, size, patch);
 			if (git_hdr_len <= len)
 				continue;
 			if (!patch->old_name && !patch->new_name) {
@@ -1481,14 +1568,14 @@ static int find_header(const char *line, unsigned long size, int *hdrsize, struc
 					       "%d leading pathname component (line %d)",
 					       "git diff header lacks filename information when removing "
 					       "%d leading pathname components (line %d)",
-					       p_value),
-					    p_value, linenr);
+					       state->p_value),
+					    state->p_value, state->linenr);
 				patch->old_name = xstrdup(patch->def_name);
 				patch->new_name = xstrdup(patch->def_name);
 			}
 			if (!patch->is_delete && !patch->new_name)
 				die("git diff header lacks filename information "
-				    "(line %d)", linenr);
+				    "(line %d)", state->linenr);
 			patch->is_toplevel_relative = 1;
 			*hdrsize = git_hdr_len;
 			return offset;
@@ -1508,37 +1595,44 @@ static int find_header(const char *line, unsigned long size, int *hdrsize, struc
 			continue;
 
 		/* Ok, we'll consider it a patch */
-		parse_traditional_patch(line, line+len, patch);
+		parse_traditional_patch(state, line, line+len, patch);
 		*hdrsize = len + nextlen;
-		linenr += 2;
+		state->linenr += 2;
 		return offset;
 	}
 	return -1;
 }
 
-static void record_ws_error(unsigned result, const char *line, int len, int linenr)
+static void record_ws_error(struct apply_state *state,
+			    unsigned result,
+			    const char *line,
+			    int len,
+			    int linenr)
 {
 	char *err;
 
 	if (!result)
 		return;
 
-	whitespace_error++;
-	if (squelch_whitespace_errors &&
-	    squelch_whitespace_errors < whitespace_error)
+	state->whitespace_error++;
+	if (state->squelch_whitespace_errors &&
+	    state->squelch_whitespace_errors < state->whitespace_error)
 		return;
 
 	err = whitespace_error_string(result);
 	fprintf(stderr, "%s:%d: %s.\n%.*s\n",
-		patch_input_file, linenr, err, len, line);
+		state->patch_input_file, linenr, err, len, line);
 	free(err);
 }
 
-static void check_whitespace(const char *line, int len, unsigned ws_rule)
+static void check_whitespace(struct apply_state *state,
+			     const char *line,
+			     int len,
+			     unsigned ws_rule)
 {
 	unsigned result = ws_check(line + 1, len - 1, ws_rule);
 
-	record_ws_error(result, line + 1, len - 2, linenr);
+	record_ws_error(state, result, line + 1, len - 2, state->linenr);
 }
 
 /*
@@ -1547,8 +1641,11 @@ static void check_whitespace(const char *line, int len, unsigned ws_rule)
  * between a "---" that is part of a patch, and a "---" that starts
  * the next patch is to look at the line counts..
  */
-static int parse_fragment(const char *line, unsigned long size,
-			  struct patch *patch, struct fragment *fragment)
+static int parse_fragment(struct apply_state *state,
+			  const char *line,
+			  unsigned long size,
+			  struct patch *patch,
+			  struct fragment *fragment)
 {
 	int added, deleted;
 	int len = linelen(line, size), offset;
@@ -1568,11 +1665,11 @@ static int parse_fragment(const char *line, unsigned long size,
 	/* Parse the thing.. */
 	line += len;
 	size -= len;
-	linenr++;
+	state->linenr++;
 	added = deleted = 0;
 	for (offset = len;
 	     0 < size;
-	     offset += len, size -= len, line += len, linenr++) {
+	     offset += len, size -= len, line += len, state->linenr++) {
 		if (!oldlines && !newlines)
 			break;
 		len = linelen(line, size);
@@ -1588,22 +1685,22 @@ static int parse_fragment(const char *line, unsigned long size,
 			if (!deleted && !added)
 				leading++;
 			trailing++;
-			if (!apply_in_reverse &&
-			    ws_error_action == correct_ws_error)
-				check_whitespace(line, len, patch->ws_rule);
+			if (!state->apply_in_reverse &&
+			    state->ws_error_action == correct_ws_error)
+				check_whitespace(state, line, len, patch->ws_rule);
 			break;
 		case '-':
-			if (apply_in_reverse &&
-			    ws_error_action != nowarn_ws_error)
-				check_whitespace(line, len, patch->ws_rule);
+			if (state->apply_in_reverse &&
+			    state->ws_error_action != nowarn_ws_error)
+				check_whitespace(state, line, len, patch->ws_rule);
 			deleted++;
 			oldlines--;
 			trailing = 0;
 			break;
 		case '+':
-			if (!apply_in_reverse &&
-			    ws_error_action != nowarn_ws_error)
-				check_whitespace(line, len, patch->ws_rule);
+			if (!state->apply_in_reverse &&
+			    state->ws_error_action != nowarn_ws_error)
+				check_whitespace(state, line, len, patch->ws_rule);
 			added++;
 			newlines--;
 			trailing = 0;
@@ -1657,7 +1754,10 @@ static int parse_fragment(const char *line, unsigned long size,
  * The (fragment->patch, fragment->size) pair points into the memory given
  * by the caller, not a copy, when we return.
  */
-static int parse_single_patch(const char *line, unsigned long size, struct patch *patch)
+static int parse_single_patch(struct apply_state *state,
+			      const char *line,
+			      unsigned long size,
+			      struct patch *patch)
 {
 	unsigned long offset = 0;
 	unsigned long oldlines = 0, newlines = 0, context = 0;
@@ -1668,10 +1768,10 @@ static int parse_single_patch(const char *line, unsigned long size, struct patch
 		int len;
 
 		fragment = xcalloc(1, sizeof(*fragment));
-		fragment->linenr = linenr;
-		len = parse_fragment(line, size, patch, fragment);
+		fragment->linenr = state->linenr;
+		len = parse_fragment(state, line, size, patch, fragment);
 		if (len <= 0)
-			die(_("corrupt patch at line %d"), linenr);
+			die(_("corrupt patch at line %d"), state->linenr);
 		fragment->patch = line;
 		fragment->size = len;
 		oldlines += fragment->oldlines;
@@ -1757,7 +1857,8 @@ static char *inflate_it(const void *data, unsigned long size,
  * points at an allocated memory that the caller must free, so
  * it is marked as "->free_patch = 1".
  */
-static struct fragment *parse_binary_hunk(char **buf_p,
+static struct fragment *parse_binary_hunk(struct apply_state *state,
+					  char **buf_p,
 					  unsigned long *sz_p,
 					  int *status_p,
 					  int *used_p)
@@ -1799,13 +1900,13 @@ static struct fragment *parse_binary_hunk(char **buf_p,
 	else
 		return NULL;
 
-	linenr++;
+	state->linenr++;
 	buffer += llen;
 	while (1) {
 		int byte_length, max_byte_length, newsize;
 		llen = linelen(buffer, size);
 		used += llen;
-		linenr++;
+		state->linenr++;
 		if (llen == 1) {
 			/* consume the blank line */
 			buffer++;
@@ -1859,7 +1960,7 @@ static struct fragment *parse_binary_hunk(char **buf_p,
 	free(data);
 	*status_p = -1;
 	error(_("corrupt binary patch at line %d: %.*s"),
-	      linenr-1, llen-1, buffer);
+	      state->linenr-1, llen-1, buffer);
 	return NULL;
 }
 
@@ -1868,7 +1969,10 @@ static struct fragment *parse_binary_hunk(char **buf_p,
  *   -1 in case of error,
  *   the length of the parsed binary patch otherwise
  */
-static int parse_binary(char *buffer, unsigned long size, struct patch *patch)
+static int parse_binary(struct apply_state *state,
+			char *buffer,
+			unsigned long size,
+			struct patch *patch)
 {
 	/*
 	 * We have read "GIT binary patch\n"; what follows is a line
@@ -1889,15 +1993,15 @@ static int parse_binary(char *buffer, unsigned long size, struct patch *patch)
 	int status;
 	int used, used_1;
 
-	forward = parse_binary_hunk(&buffer, &size, &status, &used);
+	forward = parse_binary_hunk(state, &buffer, &size, &status, &used);
 	if (!forward && !status)
 		/* there has to be one hunk (forward hunk) */
-		return error(_("unrecognized binary patch at line %d"), linenr-1);
+		return error(_("unrecognized binary patch at line %d"), state->linenr-1);
 	if (status)
 		/* otherwise we already gave an error message */
 		return status;
 
-	reverse = parse_binary_hunk(&buffer, &size, &status, &used_1);
+	reverse = parse_binary_hunk(state, &buffer, &size, &status, &used_1);
 	if (reverse)
 		used += used_1;
 	else if (status) {
@@ -1915,53 +2019,53 @@ static int parse_binary(char *buffer, unsigned long size, struct patch *patch)
 	return used;
 }
 
-static void prefix_one(char **name)
+static void prefix_one(struct apply_state *state, char **name)
 {
 	char *old_name = *name;
 	if (!old_name)
 		return;
-	*name = xstrdup(prefix_filename(prefix, prefix_length, *name));
+	*name = xstrdup(prefix_filename(state->prefix, state->prefix_length, *name));
 	free(old_name);
 }
 
-static void prefix_patch(struct patch *p)
+static void prefix_patch(struct apply_state *state, struct patch *p)
 {
-	if (!prefix || p->is_toplevel_relative)
+	if (!state->prefix || p->is_toplevel_relative)
 		return;
-	prefix_one(&p->new_name);
-	prefix_one(&p->old_name);
+	prefix_one(state, &p->new_name);
+	prefix_one(state, &p->old_name);
 }
 
 /*
  * include/exclude
  */
 
-static struct string_list limit_by_name;
-static int has_include;
-static void add_name_limit(const char *name, int exclude)
+static void add_name_limit(struct apply_state *state,
+			   const char *name,
+			   int exclude)
 {
 	struct string_list_item *it;
 
-	it = string_list_append(&limit_by_name, name);
+	it = string_list_append(&state->limit_by_name, name);
 	it->util = exclude ? NULL : (void *) 1;
 }
 
-static int use_patch(struct patch *p)
+static int use_patch(struct apply_state *state, struct patch *p)
 {
 	const char *pathname = p->new_name ? p->new_name : p->old_name;
 	int i;
 
 	/* Paths outside are not touched regardless of "--include" */
-	if (0 < prefix_length) {
+	if (0 < state->prefix_length) {
 		int pathlen = strlen(pathname);
-		if (pathlen <= prefix_length ||
-		    memcmp(prefix, pathname, prefix_length))
+		if (pathlen <= state->prefix_length ||
+		    memcmp(state->prefix, pathname, state->prefix_length))
 			return 0;
 	}
 
 	/* See if it matches any of exclude/include rule */
-	for (i = 0; i < limit_by_name.nr; i++) {
-		struct string_list_item *it = &limit_by_name.items[i];
+	for (i = 0; i < state->limit_by_name.nr; i++) {
+		struct string_list_item *it = &state->limit_by_name.items[i];
 		if (!wildmatch(it->string, pathname, 0, NULL))
 			return (it->util != NULL);
 	}
@@ -1971,7 +2075,7 @@ static int use_patch(struct patch *p)
 	 * not used.  Otherwise, we saw bunch of exclude rules (or none)
 	 * and such a path is used.
 	 */
-	return !has_include;
+	return !state->has_include;
 }
 
 
@@ -1982,25 +2086,27 @@ static int use_patch(struct patch *p)
  * Return the number of bytes consumed, so that the caller can call us
  * again for the next patch.
  */
-static int parse_chunk(char *buffer, unsigned long size, struct patch *patch)
+static int parse_chunk(struct apply_state *state, char *buffer, unsigned long size, struct patch *patch)
 {
 	int hdrsize, patchsize;
-	int offset = find_header(buffer, size, &hdrsize, patch);
+	int offset = find_header(state, buffer, size, &hdrsize, patch);
 
 	if (offset < 0)
 		return offset;
 
-	prefix_patch(patch);
+	prefix_patch(state, patch);
 
-	if (!use_patch(patch))
+	if (!use_patch(state, patch))
 		patch->ws_rule = 0;
 	else
 		patch->ws_rule = whitespace_rule(patch->new_name
 						 ? patch->new_name
 						 : patch->old_name);
 
-	patchsize = parse_single_patch(buffer + offset + hdrsize,
-				       size - offset - hdrsize, patch);
+	patchsize = parse_single_patch(state,
+				       buffer + offset + hdrsize,
+				       size - offset - hdrsize,
+				       patch);
 
 	if (!patchsize) {
 		static const char git_binary[] = "GIT binary patch\n";
@@ -2010,8 +2116,8 @@ static int parse_chunk(char *buffer, unsigned long size, struct patch *patch)
 		if (llen == sizeof(git_binary) - 1 &&
 		    !memcmp(git_binary, buffer + hd, llen)) {
 			int used;
-			linenr++;
-			used = parse_binary(buffer + hd + llen,
+			state->linenr++;
+			used = parse_binary(state, buffer + hd + llen,
 					    size - hd - llen, patch);
 			if (used < 0)
 				return -1;
@@ -2031,7 +2137,7 @@ static int parse_chunk(char *buffer, unsigned long size, struct patch *patch)
 				int len = strlen(binhdr[i]);
 				if (len < size - hd &&
 				    !memcmp(binhdr[i], buffer + hd, len)) {
-					linenr++;
+					state->linenr++;
 					patch->is_binary = 1;
 					patchsize = llen;
 					break;
@@ -2043,9 +2149,9 @@ static int parse_chunk(char *buffer, unsigned long size, struct patch *patch)
 		 * without metadata change.  A binary patch appears
 		 * empty to us here.
 		 */
-		if ((apply || check) &&
+		if ((state->apply || state->check) &&
 		    (!patch->is_binary && !metadata_changes(patch)))
-			die(_("patch with only garbage at line %d"), linenr);
+			die(_("patch with only garbage at line %d"), state->linenr);
 	}
 
 	return offset + hdrsize + patchsize;
@@ -2083,7 +2189,7 @@ static const char pluses[] =
 static const char minuses[]=
 "----------------------------------------------------------------------";
 
-static void show_stats(struct patch *patch)
+static void show_stats(struct apply_state *state, struct patch *patch)
 {
 	struct strbuf qname = STRBUF_INIT;
 	char *cp = patch->new_name ? patch->new_name : patch->old_name;
@@ -2094,7 +2200,7 @@ static void show_stats(struct patch *patch)
 	/*
 	 * "scale" the filename
 	 */
-	max = max_len;
+	max = state->max_len;
 	if (max > 50)
 		max = 50;
 
@@ -2117,13 +2223,13 @@ static void show_stats(struct patch *patch)
 	/*
 	 * scale the add/delete
 	 */
-	max = max + max_change > 70 ? 70 - max : max_change;
+	max = max + state->max_change > 70 ? 70 - max : state->max_change;
 	add = patch->lines_added;
 	del = patch->lines_deleted;
 
-	if (max_change > 0) {
-		int total = ((add + del) * max + max_change / 2) / max_change;
-		add = (add * max + max_change / 2) / max_change;
+	if (state->max_change > 0) {
+		int total = ((add + del) * max + state->max_change / 2) / state->max_change;
+		add = (add * max + state->max_change / 2) / state->max_change;
 		del = total - add;
 	}
 	printf("%5d %.*s%.*s\n", patch->lines_added + patch->lines_deleted,
@@ -2194,17 +2300,17 @@ static void update_pre_post_images(struct image *preimage,
 	fixed = preimage->buf;
 
 	for (i = reduced = ctx = 0; i < postimage->nr; i++) {
-		size_t len = postimage->line[i].len;
+		size_t l_len = postimage->line[i].len;
 		if (!(postimage->line[i].flag & LINE_COMMON)) {
 			/* an added line -- no counterparts in preimage */
-			memmove(new, old, len);
-			old += len;
-			new += len;
+			memmove(new, old, l_len);
+			old += l_len;
+			new += l_len;
 			continue;
 		}
 
 		/* a common context -- skip it in the original postimage */
-		old += len;
+		old += l_len;
 
 		/* and find the corresponding one in the fixed preimage */
 		while (ctx < preimage->nr &&
@@ -2223,11 +2329,11 @@ static void update_pre_post_images(struct image *preimage,
 		}
 
 		/* and copy it in, while fixing the line length */
-		len = preimage->line[ctx].len;
-		memcpy(new, fixed, len);
-		new += len;
-		fixed += len;
-		postimage->line[i].len = len;
+		l_len = preimage->line[ctx].len;
+		memcpy(new, fixed, l_len);
+		new += l_len;
+		fixed += l_len;
+		postimage->line[i].len = l_len;
 		ctx++;
 	}
 
@@ -2242,7 +2348,76 @@ static void update_pre_post_images(struct image *preimage,
 	postimage->nr -= reduced;
 }
 
-static int match_fragment(struct image *img,
+static int line_by_line_fuzzy_match(struct image *img,
+				    struct image *preimage,
+				    struct image *postimage,
+				    unsigned long try,
+				    int try_lno,
+				    int preimage_limit)
+{
+	int i;
+	size_t imgoff = 0;
+	size_t preoff = 0;
+	size_t postlen = postimage->len;
+	size_t extra_chars;
+	char *buf;
+	char *preimage_eof;
+	char *preimage_end;
+	struct strbuf fixed;
+	char *fixed_buf;
+	size_t fixed_len;
+
+	for (i = 0; i < preimage_limit; i++) {
+		size_t prelen = preimage->line[i].len;
+		size_t imglen = img->line[try_lno+i].len;
+
+		if (!fuzzy_matchlines(img->buf + try + imgoff, imglen,
+				      preimage->buf + preoff, prelen))
+			return 0;
+		if (preimage->line[i].flag & LINE_COMMON)
+			postlen += imglen - prelen;
+		imgoff += imglen;
+		preoff += prelen;
+	}
+
+	/*
+	 * Ok, the preimage matches with whitespace fuzz.
+	 *
+	 * imgoff now holds the true length of the target that
+	 * matches the preimage before the end of the file.
+	 *
+	 * Count the number of characters in the preimage that fall
+	 * beyond the end of the file and make sure that all of them
+	 * are whitespace characters. (This can only happen if
+	 * we are removing blank lines at the end of the file.)
+	 */
+	buf = preimage_eof = preimage->buf + preoff;
+	for ( ; i < preimage->nr; i++)
+		preoff += preimage->line[i].len;
+	preimage_end = preimage->buf + preoff;
+	for ( ; buf < preimage_end; buf++)
+		if (!isspace(*buf))
+			return 0;
+
+	/*
+	 * Update the preimage and the common postimage context
+	 * lines to use the same whitespace as the target.
+	 * If whitespace is missing in the target (i.e.
+	 * if the preimage extends beyond the end of the file),
+	 * use the whitespace from the preimage.
+	 */
+	extra_chars = preimage_end - preimage_eof;
+	strbuf_init(&fixed, imgoff + extra_chars);
+	strbuf_add(&fixed, img->buf + try, imgoff);
+	strbuf_add(&fixed, preimage_eof, extra_chars);
+	fixed_buf = strbuf_detach(&fixed, &fixed_len);
+	update_pre_post_images(preimage, postimage,
+			       fixed_buf, fixed_len, postlen);
+	return 1;
+}
+
+static int match_fragment(struct apply_state *state,
+			  struct image *img,
 			  struct image *preimage,
 			  struct image *postimage,
 			  unsigned long try,
@@ -2263,7 +2438,7 @@ static int match_fragment(struct image *img,
 		preimage_limit = preimage->nr;
 		if (match_end && (preimage->nr + try_lno != img->nr))
 			return 0;
-	} else if (ws_error_action == correct_ws_error &&
+	} else if (state->ws_error_action == correct_ws_error &&
 		   (ws_rule & WS_BLANK_AT_EOF)) {
 		/*
 		 * This hunk extends beyond the end of img, and we are
@@ -2331,63 +2506,11 @@ static int match_fragment(struct image *img,
 	 * fuzzy matching. We collect all the line length information because
 	 * we need it to adjust whitespace if we match.
 	 */
-	if (ws_ignore_action == ignore_ws_change) {
-		size_t imgoff = 0;
-		size_t preoff = 0;
-		size_t postlen = postimage->len;
-		size_t extra_chars;
-		char *preimage_eof;
-		char *preimage_end;
-		for (i = 0; i < preimage_limit; i++) {
-			size_t prelen = preimage->line[i].len;
-			size_t imglen = img->line[try_lno+i].len;
-
-			if (!fuzzy_matchlines(img->buf + try + imgoff, imglen,
-					      preimage->buf + preoff, prelen))
-				return 0;
-			if (preimage->line[i].flag & LINE_COMMON)
-				postlen += imglen - prelen;
-			imgoff += imglen;
-			preoff += prelen;
-		}
+	if (state->ws_ignore_action == ignore_ws_change)
+		return line_by_line_fuzzy_match(img, preimage, postimage,
+						try, try_lno, preimage_limit);
 
-		/*
-		 * Ok, the preimage matches with whitespace fuzz.
-		 *
-		 * imgoff now holds the true length of the target that
-		 * matches the preimage before the end of the file.
-		 *
-		 * Count the number of characters in the preimage that fall
-		 * beyond the end of the file and make sure that all of them
-		 * are whitespace characters. (This can only happen if
-		 * we are removing blank lines at the end of the file.)
-		 */
-		buf = preimage_eof = preimage->buf + preoff;
-		for ( ; i < preimage->nr; i++)
-			preoff += preimage->line[i].len;
-		preimage_end = preimage->buf + preoff;
-		for ( ; buf < preimage_end; buf++)
-			if (!isspace(*buf))
-				return 0;
-
-		/*
-		 * Update the preimage and the common postimage context
-		 * lines to use the same whitespace as the target.
-		 * If whitespace is missing in the target (i.e.
-		 * if the preimage extends beyond the end of the file),
-		 * use the whitespace from the preimage.
-		 */
-		extra_chars = preimage_end - preimage_eof;
-		strbuf_init(&fixed, imgoff + extra_chars);
-		strbuf_add(&fixed, img->buf + try, imgoff);
-		strbuf_add(&fixed, preimage_eof, extra_chars);
-		fixed_buf = strbuf_detach(&fixed, &fixed_len);
-		update_pre_post_images(preimage, postimage,
-				fixed_buf, fixed_len, postlen);
-		return 1;
-	}
-
-	if (ws_error_action != correct_ws_error)
+	if (state->ws_error_action != correct_ws_error)
 		return 0;
 
 	/*
@@ -2499,7 +2622,8 @@ static int match_fragment(struct image *img,
 	return 0;
 }
 
-static int find_pos(struct image *img,
+static int find_pos(struct apply_state *state,
+		    struct image *img,
 		    struct image *preimage,
 		    struct image *postimage,
 		    int line,
@@ -2543,7 +2667,7 @@ static int find_pos(struct image *img,
 	try_lno = line;
 
 	for (i = 0; ; i++) {
-		if (match_fragment(img, preimage, postimage,
+		if (match_fragment(state, img, preimage, postimage,
 				   try, try_lno, ws_rule,
 				   match_beginning, match_end))
 			return try_lno;
@@ -2594,7 +2718,8 @@ static void remove_last_line(struct image *img)
  * apply at applied_pos (counts in line numbers) in "img".
  * Update "img" to remove "preimage" and replace it with "postimage".
  */
-static void update_image(struct image *img,
+static void update_image(struct apply_state *state,
+			 struct image *img,
 			 int applied_pos,
 			 struct image *preimage,
 			 struct image *postimage)
@@ -2659,7 +2784,7 @@ static void update_image(struct image *img,
 	memcpy(img->line + applied_pos,
 	       postimage->line,
 	       postimage->nr * sizeof(*img->line));
-	if (!allow_overlap)
+	if (!state->allow_overlap)
 		for (i = 0; i < postimage->nr; i++)
 			img->line[applied_pos + i].flag |= LINE_PATCHED;
 	img->nr = nr;
@@ -2670,7 +2795,8 @@ static void update_image(struct image *img,
  * postimage) for the hunk.  Find lines that match "preimage" in "img" and
  * replace the part of "img" with "postimage" text.
  */
-static int apply_one_fragment(struct image *img, struct fragment *frag,
+static int apply_one_fragment(struct apply_state *state,
+			      struct image *img, struct fragment *frag,
 			      int inaccurate_eof, unsigned ws_rule,
 			      int nth_fragment)
 {
@@ -2715,7 +2841,7 @@ static int apply_one_fragment(struct image *img, struct fragment *frag,
 		if (len < size && patch[len] == '\\')
 			plen--;
 		first = *patch;
-		if (apply_in_reverse) {
+		if (state->apply_in_reverse) {
 			if (first == '-')
 				first = '+';
 			else if (first == '+')
@@ -2748,17 +2874,17 @@ static int apply_one_fragment(struct image *img, struct fragment *frag,
 		/* Fall-through for ' ' */
 		case '+':
 			/* --no-add does not add new lines */
-			if (first == '+' && no_add)
+			if (first == '+' && state->no_add)
 				break;
 
 			start = newlines.len;
 			if (first != '+' ||
-			    !whitespace_error ||
-			    ws_error_action != correct_ws_error) {
+			    !state->whitespace_error ||
+			    state->ws_error_action != correct_ws_error) {
 				strbuf_add(&newlines, patch + 1, plen);
 			}
 			else {
-				ws_fix_copy(&newlines, patch + 1, plen, ws_rule, &applied_after_fixing_ws);
+				ws_fix_copy(&newlines, patch + 1, plen, ws_rule, &state->applied_after_fixing_ws);
 			}
 			add_line_info(&postimage, newlines.buf + start, newlines.len - start,
 				      (first == '+' ? 0 : LINE_COMMON));
@@ -2771,7 +2897,7 @@ static int apply_one_fragment(struct image *img, struct fragment *frag,
 			/* Ignore it, we already handled it */
 			break;
 		default:
-			if (apply_verbosely)
+			if (state->apply_verbosely)
 				error(_("invalid start of line: '%c'"), first);
 			applied_pos = -1;
 			goto out;
@@ -2812,7 +2938,7 @@ static int apply_one_fragment(struct image *img, struct fragment *frag,
 	 * without leading context must match at the beginning.
 	 */
 	match_beginning = (!frag->oldpos ||
-			   (frag->oldpos == 1 && !unidiff_zero));
+			   (frag->oldpos == 1 && !state->unidiff_zero));
 
 	/*
 	 * A hunk without trailing lines must match at the end.
@@ -2820,7 +2946,7 @@ static int apply_one_fragment(struct image *img, struct fragment *frag,
 	 * from the lack of trailing lines if the patch was generated
 	 * with unidiff without any context.
 	 */
-	match_end = !unidiff_zero && !trailing;
+	match_end = !state->unidiff_zero && !trailing;
 
 	pos = frag->newpos ? (frag->newpos - 1) : 0;
 	preimage.buf = oldlines;
@@ -2832,14 +2958,14 @@ static int apply_one_fragment(struct image *img, struct fragment *frag,
 
 	for (;;) {
 
-		applied_pos = find_pos(img, &preimage, &postimage, pos,
+		applied_pos = find_pos(state, img, &preimage, &postimage, pos,
 				       ws_rule, match_beginning, match_end);
 
 		if (applied_pos >= 0)
 			break;
 
 		/* Am I at my context limits? */
-		if ((leading <= p_context) && (trailing <= p_context))
+		if ((leading <= state->p_context) && (trailing <= state->p_context))
 			break;
 		if (match_beginning || match_end) {
 			match_beginning = match_end = 0;
@@ -2868,10 +2994,10 @@ static int apply_one_fragment(struct image *img, struct fragment *frag,
 		if (new_blank_lines_at_end &&
 		    preimage.nr + applied_pos >= img->nr &&
 		    (ws_rule & WS_BLANK_AT_EOF) &&
-		    ws_error_action != nowarn_ws_error) {
-			record_ws_error(WS_BLANK_AT_EOF, "+", 1,
+		    state->ws_error_action != nowarn_ws_error) {
+			record_ws_error(state, WS_BLANK_AT_EOF, "+", 1,
 					found_new_blank_lines_at_end);
-			if (ws_error_action == correct_ws_error) {
+			if (state->ws_error_action == correct_ws_error) {
 				while (new_blank_lines_at_end--)
 					remove_last_line(&postimage);
 			}
@@ -2882,13 +3008,13 @@ static int apply_one_fragment(struct image *img, struct fragment *frag,
 			 * apply_patch->check_patch_list->check_patch->
 			 * apply_data->apply_fragments->apply_one_fragment
 			 */
-			if (ws_error_action == die_on_ws_error)
-				apply = 0;
+			if (state->ws_error_action == die_on_ws_error)
+				state->apply = 0;
 		}
 
-		if (apply_verbosely && applied_pos != pos) {
+		if (state->apply_verbosely && applied_pos != pos) {
 			int offset = applied_pos - pos;
-			if (apply_in_reverse)
+			if (state->apply_in_reverse)
 				offset = 0 - offset;
 			fprintf_ln(stderr,
 				   Q_("Hunk #%d succeeded at %d (offset %d line).",
@@ -2906,9 +3032,9 @@ static int apply_one_fragment(struct image *img, struct fragment *frag,
 			fprintf_ln(stderr, _("Context reduced to (%ld/%ld)"
 					     " to apply fragment at %d"),
 				   leading, trailing, applied_pos+1);
-		update_image(img, applied_pos, &preimage, &postimage);
+		update_image(state, img, applied_pos, &preimage, &postimage);
 	} else {
-		if (apply_verbosely)
+		if (state->apply_verbosely)
 			error(_("while searching for:\n%.*s"),
 			      (int)(old - oldlines), oldlines);
 	}
@@ -2922,7 +3048,9 @@ out:
 	return (applied_pos < 0);
 }
 
-static int apply_binary_fragment(struct image *img, struct patch *patch)
+static int apply_binary_fragment(struct apply_state *state,
+				 struct image *img,
+				 struct patch *patch)
 {
 	struct fragment *fragment = patch->fragments;
 	unsigned long len;
@@ -2935,7 +3063,7 @@ static int apply_binary_fragment(struct image *img, struct patch *patch)
 			     patch->old_name);
 
 	/* Binary patch is irreversible without the optional second hunk */
-	if (apply_in_reverse) {
+	if (state->apply_in_reverse) {
 		if (!fragment->next)
 			return error("cannot reverse-apply a binary patch "
 				     "without the reverse hunk to '%s'",
@@ -2968,7 +3096,9 @@ static int apply_binary_fragment(struct image *img, struct patch *patch)
  * but the preimage prepared by the caller in "img" is freed here
  * or in the helper function apply_binary_fragment() this calls.
  */
-static int apply_binary(struct image *img, struct patch *patch)
+static int apply_binary(struct apply_state *state,
+			struct image *img,
+			struct patch *patch)
 {
 	const char *name = patch->old_name ? patch->old_name : patch->new_name;
 	unsigned char sha1[20];
@@ -3029,7 +3159,7 @@ static int apply_binary(struct image *img, struct patch *patch)
 		 * apply the patch data to it, which is stored
 		 * in the patch->fragments->{patch,size}.
 		 */
-		if (apply_binary_fragment(img, patch))
+		if (apply_binary_fragment(state, img, patch))
 			return error(_("binary patch does not apply to '%s'"),
 				     name);
 
@@ -3043,7 +3173,7 @@ static int apply_binary(struct image *img, struct patch *patch)
 	return 0;
 }
 
-static int apply_fragments(struct image *img, struct patch *patch)
+static int apply_fragments(struct apply_state *state, struct image *img, struct patch *patch)
 {
 	struct fragment *frag = patch->fragments;
 	const char *name = patch->old_name ? patch->old_name : patch->new_name;
@@ -3052,13 +3182,13 @@ static int apply_fragments(struct image *img, struct patch *patch)
 	int nth = 0;
 
 	if (patch->is_binary)
-		return apply_binary(img, patch);
+		return apply_binary(state, img, patch);
 
 	while (frag) {
 		nth++;
-		if (apply_one_fragment(img, frag, inaccurate_eof, ws_rule, nth)) {
+		if (apply_one_fragment(state, img, frag, inaccurate_eof, ws_rule, nth)) {
 			error(_("patch failed: %s:%ld"), name, frag->oldpos);
-			if (!apply_with_reject)
+			if (!state->apply_with_reject)
 				return -1;
 			frag->rejected = 1;
 		}
@@ -3093,14 +3223,14 @@ static int read_file_or_gitlink(const struct cache_entry *ce, struct strbuf *buf
 	return read_blob_object(buf, ce->sha1, ce->ce_mode);
 }
 
-static struct patch *in_fn_table(const char *name)
+static struct patch *in_fn_table(struct apply_state *state, const char *name)
 {
 	struct string_list_item *item;
 
 	if (name == NULL)
 		return NULL;
 
-	item = string_list_lookup(&fn_table, name);
+	item = string_list_lookup(&state->fn_table, name);
 	if (item != NULL)
 		return (struct patch *)item->util;
 
@@ -3132,7 +3262,7 @@ static int was_deleted(struct patch *patch)
 	return patch == PATH_WAS_DELETED;
 }
 
-static void add_to_fn_table(struct patch *patch)
+static void add_to_fn_table(struct apply_state *state, struct patch *patch)
 {
 	struct string_list_item *item;
 
@@ -3142,7 +3272,7 @@ static void add_to_fn_table(struct patch *patch)
 	 * file creations and copies
 	 */
 	if (patch->new_name != NULL) {
-		item = string_list_insert(&fn_table, patch->new_name);
+		item = string_list_insert(&state->fn_table, patch->new_name);
 		item->util = patch;
 	}
 
@@ -3151,12 +3281,12 @@ static void add_to_fn_table(struct patch *patch)
 	 * later chunks shouldn't patch old names
 	 */
 	if ((patch->new_name == NULL) || (patch->is_rename)) {
-		item = string_list_insert(&fn_table, patch->old_name);
+		item = string_list_insert(&state->fn_table, patch->old_name);
 		item->util = PATH_WAS_DELETED;
 	}
 }
 
-static void prepare_fn_table(struct patch *patch)
+static void prepare_fn_table(struct apply_state *state, struct patch *patch)
 {
 	/*
 	 * store information about incoming file deletion
@@ -3164,7 +3294,7 @@ static void prepare_fn_table(struct patch *patch)
 	while (patch) {
 		if ((patch->new_name == NULL) || (patch->is_rename)) {
 			struct string_list_item *item;
-			item = string_list_insert(&fn_table, patch->old_name);
+			item = string_list_insert(&state->fn_table, patch->old_name);
 			item->util = PATH_TO_BE_DELETED;
 		}
 		patch = patch->next;
@@ -3185,7 +3315,9 @@ static int checkout_target(struct index_state *istate,
 	return 0;
 }
 
-static struct patch *previous_patch(struct patch *patch, int *gone)
+static struct patch *previous_patch(struct apply_state *state,
+				    struct patch *patch,
+				    int *gone)
 {
 	struct patch *previous;
 
@@ -3193,7 +3325,7 @@ static struct patch *previous_patch(struct patch *patch, int *gone)
 	if (patch->is_copy || patch->is_rename)
 		return NULL; /* "git" patches do not depend on the order */
 
-	previous = in_fn_table(patch->old_name);
+	previous = in_fn_table(state, patch->old_name);
 	if (!previous)
 		return NULL;
 
@@ -3218,13 +3350,14 @@ static int verify_index_match(const struct cache_entry *ce, struct stat *st)
 
 #define SUBMODULE_PATCH_WITHOUT_INDEX 1
 
-static int load_patch_target(struct strbuf *buf,
+static int load_patch_target(struct apply_state *state,
+			     struct strbuf *buf,
 			     const struct cache_entry *ce,
 			     struct stat *st,
 			     const char *name,
 			     unsigned expected_mode)
 {
-	if (cached || check_index) {
+	if (state->cached || state->check_index) {
 		if (read_file_or_gitlink(ce, buf))
 			return error(_("read of %s failed"), name);
 	} else if (name) {
@@ -3250,7 +3383,8 @@ static int load_patch_target(struct strbuf *buf,
  * applying a non-git patch that incrementally updates the tree,
  * we read from the result of a previous diff.
  */
-static int load_preimage(struct image *image,
+static int load_preimage(struct apply_state *state,
+			 struct image *image,
 			 struct patch *patch, struct stat *st,
 			 const struct cache_entry *ce)
 {
@@ -3260,7 +3394,7 @@ static int load_preimage(struct image *image,
 	struct patch *previous;
 	int status;
 
-	previous = previous_patch(patch, &status);
+	previous = previous_patch(state, patch, &status);
 	if (status)
 		return error(_("path %s has been renamed/deleted"),
 			     patch->old_name);
@@ -3268,7 +3402,7 @@ static int load_preimage(struct image *image,
 		/* We have a patched copy in memory; use that. */
 		strbuf_add(&buf, previous->result, previous->resultsize);
 	} else {
-		status = load_patch_target(&buf, ce, st,
+		status = load_patch_target(state, &buf, ce, st,
 					   patch->old_name, patch->old_mode);
 		if (status < 0)
 			return status;
@@ -3327,7 +3461,9 @@ static int three_way_merge(struct image *image,
  * the current contents of the new_name.  In no cases other than that
  * this function will be called.
  */
-static int load_current(struct image *image, struct patch *patch)
+static int load_current(struct apply_state *state,
+			struct image *image,
+			struct patch *patch)
 {
 	struct strbuf buf = STRBUF_INIT;
 	int status, pos;
@@ -3354,7 +3490,7 @@ static int load_current(struct image *image, struct patch *patch)
 	if (verify_index_match(ce, &st))
 		return error(_("%s: does not match index"), name);
 
-	status = load_patch_target(&buf, ce, &st, name, mode);
+	status = load_patch_target(state, &buf, ce, &st, name, mode);
 	if (status < 0)
 		return status;
 	else if (status)
@@ -3364,8 +3500,11 @@ static int load_current(struct image *image, struct patch *patch)
 	return 0;
 }
 
-static int try_threeway(struct image *image, struct patch *patch,
-			struct stat *st, const struct cache_entry *ce)
+static int try_threeway(struct apply_state *state,
+			struct image *image,
+			struct patch *patch,
+			struct stat *st,
+			const struct cache_entry *ce)
 {
 	unsigned char pre_sha1[20], post_sha1[20], our_sha1[20];
 	struct strbuf buf = STRBUF_INIT;
@@ -3391,7 +3530,7 @@ static int try_threeway(struct image *image, struct patch *patch,
 	img = strbuf_detach(&buf, &len);
 	prepare_image(&tmp_image, img, len, 1);
 	/* Apply the patch to get the post image */
-	if (apply_fragments(&tmp_image, patch) < 0) {
+	if (apply_fragments(state, &tmp_image, patch) < 0) {
 		clear_image(&tmp_image);
 		return -1;
 	}
@@ -3401,11 +3540,11 @@ static int try_threeway(struct image *image, struct patch *patch,
 
 	/* our_sha1[] is ours */
 	if (patch->is_new) {
-		if (load_current(&tmp_image, patch))
+		if (load_current(state, &tmp_image, patch))
 			return error("cannot read the current contents of '%s'",
 				     patch->new_name);
 	} else {
-		if (load_preimage(&tmp_image, patch, st, ce))
+		if (load_preimage(state, &tmp_image, patch, st, ce))
 			return error("cannot read the current contents of '%s'",
 				     patch->old_name);
 	}
@@ -3435,22 +3574,23 @@ static int try_threeway(struct image *image, struct patch *patch,
 	return 0;
 }
 
-static int apply_data(struct patch *patch, struct stat *st, const struct cache_entry *ce)
+static int apply_data(struct apply_state *state, struct patch *patch,
+		      struct stat *st, const struct cache_entry *ce)
 {
 	struct image image;
 
-	if (load_preimage(&image, patch, st, ce) < 0)
+	if (load_preimage(state, &image, patch, st, ce) < 0)
 		return -1;
 
 	if (patch->direct_to_threeway ||
-	    apply_fragments(&image, patch) < 0) {
+	    apply_fragments(state, &image, patch) < 0) {
 		/* Note: with --reject, apply_fragments() returns 0 */
-		if (!threeway || try_threeway(&image, patch, st, ce) < 0)
+		if (!state->threeway || try_threeway(state, &image, patch, st, ce) < 0)
 			return -1;
 	}
 	patch->result = image.buf;
 	patch->resultsize = image.len;
-	add_to_fn_table(patch);
+	add_to_fn_table(state, patch);
 	free(image.line_allocated);
 
 	if (0 < patch->is_delete && patch->resultsize)
@@ -3470,7 +3610,10 @@ static int apply_data(struct patch *patch, struct stat *st, const struct cache_e
  * check_patch() separately makes sure (and errors out otherwise) that
  * the path the patch creates does not exist in the current tree.
  */
-static int check_preimage(struct patch *patch, struct cache_entry **ce, struct stat *st)
+static int check_preimage(struct apply_state *state,
+			  struct patch *patch,
+			  struct cache_entry **ce,
+			  struct stat *st)
 {
 	const char *old_name = patch->old_name;
 	struct patch *previous = NULL;
@@ -3481,19 +3624,19 @@ static int check_preimage(struct patch *patch, struct cache_entry **ce, struct s
 		return 0;
 
 	assert(patch->is_new <= 0);
-	previous = previous_patch(patch, &status);
+	previous = previous_patch(state, patch, &status);
 
 	if (status)
 		return error(_("path %s has been renamed/deleted"), old_name);
 	if (previous) {
 		st_mode = previous->new_mode;
-	} else if (!cached) {
+	} else if (!state->cached) {
 		stat_ret = lstat(old_name, st);
 		if (stat_ret && errno != ENOENT)
 			return error(_("%s: %s"), old_name, strerror(errno));
 	}
 
-	if (check_index && !previous) {
+	if (state->check_index && !previous) {
 		int pos = cache_name_pos(old_name, strlen(old_name));
 		if (pos < 0) {
 			if (patch->is_new < 0)
@@ -3505,9 +3648,9 @@ static int check_preimage(struct patch *patch, struct cache_entry **ce, struct s
 			if (checkout_target(&the_index, *ce, st))
 				return -1;
 		}
-		if (!cached && verify_index_match(*ce, st))
+		if (!state->cached && verify_index_match(*ce, st))
 			return error(_("%s: does not match index"), old_name);
-		if (cached)
+		if (state->cached)
 			st_mode = (*ce)->ce_mode;
 	} else if (stat_ret < 0) {
 		if (patch->is_new < 0)
@@ -3515,7 +3658,7 @@ static int check_preimage(struct patch *patch, struct cache_entry **ce, struct s
 		return error(_("%s: %s"), old_name, strerror(errno));
 	}
 
-	if (!cached && !previous)
+	if (!state->cached && !previous)
 		st_mode = ce_mode_from_stat(*ce, st->st_mode);
 
 	if (patch->is_new < 0)
@@ -3543,15 +3686,17 @@ static int check_preimage(struct patch *patch, struct cache_entry **ce, struct s
 #define EXISTS_IN_INDEX 1
 #define EXISTS_IN_WORKTREE 2
 
-static int check_to_create(const char *new_name, int ok_if_exists)
+static int check_to_create(struct apply_state *state,
+			   const char *new_name,
+			   int ok_if_exists)
 {
 	struct stat nst;
 
-	if (check_index &&
+	if (state->check_index &&
 	    cache_name_pos(new_name, strlen(new_name)) >= 0 &&
 	    !ok_if_exists)
 		return EXISTS_IN_INDEX;
-	if (cached)
+	if (state->cached)
 		return 0;
 
 	if (!lstat(new_name, &nst)) {
@@ -3574,56 +3719,46 @@ static int check_to_create(const char *new_name, int ok_if_exists)
 	return 0;
 }
 
-/*
- * We need to keep track of how symlinks in the preimage are
- * manipulated by the patches.  A patch to add a/b/c where a/b
- * is a symlink should not be allowed to affect the directory
- * the symlink points at, but if the same patch removes a/b,
- * it is perfectly fine, as the patch removes a/b to make room
- * to create a directory a/b so that a/b/c can be created.
- */
-static struct string_list symlink_changes;
-#define SYMLINK_GOES_AWAY 01
-#define SYMLINK_IN_RESULT 02
-
-static uintptr_t register_symlink_changes(const char *path, uintptr_t what)
+static uintptr_t register_symlink_changes(struct apply_state *state,
+					  const char *path,
+					  uintptr_t what)
 {
 	struct string_list_item *ent;
 
-	ent = string_list_lookup(&symlink_changes, path);
+	ent = string_list_lookup(&state->symlink_changes, path);
 	if (!ent) {
-		ent = string_list_insert(&symlink_changes, path);
+		ent = string_list_insert(&state->symlink_changes, path);
 		ent->util = (void *)0;
 	}
 	ent->util = (void *)(what | ((uintptr_t)ent->util));
 	return (uintptr_t)ent->util;
 }
 
-static uintptr_t check_symlink_changes(const char *path)
+static uintptr_t check_symlink_changes(struct apply_state *state, const char *path)
 {
 	struct string_list_item *ent;
 
-	ent = string_list_lookup(&symlink_changes, path);
+	ent = string_list_lookup(&state->symlink_changes, path);
 	if (!ent)
 		return 0;
 	return (uintptr_t)ent->util;
 }
 
-static void prepare_symlink_changes(struct patch *patch)
+static void prepare_symlink_changes(struct apply_state *state, struct patch *patch)
 {
 	for ( ; patch; patch = patch->next) {
 		if ((patch->old_name && S_ISLNK(patch->old_mode)) &&
 		    (patch->is_rename || patch->is_delete))
 			/* the symlink at patch->old_name is removed */
-			register_symlink_changes(patch->old_name, SYMLINK_GOES_AWAY);
+			register_symlink_changes(state, patch->old_name, SYMLINK_GOES_AWAY);
 
 		if (patch->new_name && S_ISLNK(patch->new_mode))
 			/* the symlink at patch->new_name is created or remains */
-			register_symlink_changes(patch->new_name, SYMLINK_IN_RESULT);
+			register_symlink_changes(state, patch->new_name, SYMLINK_IN_RESULT);
 	}
 }
 
-static int path_is_beyond_symlink_1(struct strbuf *name)
+static int path_is_beyond_symlink_1(struct apply_state *state, struct strbuf *name)
 {
 	do {
 		unsigned int change;
@@ -3633,7 +3768,7 @@ static int path_is_beyond_symlink_1(struct strbuf *name)
 		if (!name->len)
 			break;
 		name->buf[name->len] = '\0';
-		change = check_symlink_changes(name->buf);
+		change = check_symlink_changes(state, name->buf);
 		if (change & SYMLINK_IN_RESULT)
 			return 1;
 		if (change & SYMLINK_GOES_AWAY)
@@ -3644,7 +3779,7 @@ static int path_is_beyond_symlink_1(struct strbuf *name)
 			continue;
 
 		/* otherwise, check the preimage */
-		if (check_index) {
+		if (state->check_index) {
 			struct cache_entry *ce;
 
 			ce = cache_file_exists(name->buf, name->len, ignore_case);
@@ -3659,14 +3794,14 @@ static int path_is_beyond_symlink_1(struct strbuf *name)
 	return 0;
 }
 
-static int path_is_beyond_symlink(const char *name_)
+static int path_is_beyond_symlink(struct apply_state *state, const char *name_)
 {
 	int ret;
 	struct strbuf name = STRBUF_INIT;
 
 	assert(*name_ != '\0');
 	strbuf_addstr(&name, name_);
-	ret = path_is_beyond_symlink_1(&name);
+	ret = path_is_beyond_symlink_1(state, &name);
 	strbuf_release(&name);
 
 	return ret;
@@ -3693,7 +3828,7 @@ static void die_on_unsafe_path(struct patch *patch)
  * Check and apply the patch in-core; leave the result in patch->result
  * for the caller to write it out to the final destination.
  */
-static int check_patch(struct patch *patch)
+static int check_patch(struct apply_state *state, struct patch *patch)
 {
 	struct stat st;
 	const char *old_name = patch->old_name;
@@ -3706,7 +3841,7 @@ static int check_patch(struct patch *patch)
 
 	patch->rejected = 1; /* we will drop this after we succeed */
 
-	status = check_preimage(patch, &ce, &st);
+	status = check_preimage(state, patch, &ce, &st);
 	if (status)
 		return status;
 	old_name = patch->old_name;
@@ -3725,7 +3860,7 @@ static int check_patch(struct patch *patch)
 	 * B and rename from A to B is handled the same way by asking
 	 * was_deleted().
 	 */
-	if ((tpatch = in_fn_table(new_name)) &&
+	if ((tpatch = in_fn_table(state, new_name)) &&
 	    (was_deleted(tpatch) || to_be_deleted(tpatch)))
 		ok_if_exists = 1;
 	else
@@ -3733,9 +3868,9 @@ static int check_patch(struct patch *patch)
 
 	if (new_name &&
 	    ((0 < patch->is_new) || patch->is_rename || patch->is_copy)) {
-		int err = check_to_create(new_name, ok_if_exists);
+		int err = check_to_create(state, new_name, ok_if_exists);
 
-		if (err && threeway) {
+		if (err && state->threeway) {
 			patch->direct_to_threeway = 1;
 		} else switch (err) {
 		case 0:
@@ -3776,7 +3911,7 @@ static int check_patch(struct patch *patch)
 		}
 	}
 
-	if (!unsafe_paths)
+	if (!state->unsafe_paths)
 		die_on_unsafe_path(patch);
 
 	/*
@@ -3788,27 +3923,27 @@ static int check_patch(struct patch *patch)
 	 * is not deposited to a path that is beyond a symbolic link
 	 * here.
 	 */
-	if (!patch->is_delete && path_is_beyond_symlink(patch->new_name))
+	if (!patch->is_delete && path_is_beyond_symlink(state, patch->new_name))
 		return error(_("affected file '%s' is beyond a symbolic link"),
 			     patch->new_name);
 
-	if (apply_data(patch, &st, ce) < 0)
+	if (apply_data(state, patch, &st, ce) < 0)
 		return error(_("%s: patch does not apply"), name);
 	patch->rejected = 0;
 	return 0;
 }
 
-static int check_patch_list(struct patch *patch)
+static int check_patch_list(struct apply_state *state, struct patch *patch)
 {
 	int err = 0;
 
-	prepare_symlink_changes(patch);
-	prepare_fn_table(patch);
+	prepare_symlink_changes(state, patch);
+	prepare_fn_table(state, patch);
 	while (patch) {
-		if (apply_verbosely)
+		if (state->apply_verbosely)
 			say_patch_name(stderr,
 				       _("Checking patch %s..."), patch);
-		err |= check_patch(patch);
+		err |= check_patch(state, patch);
 		patch = patch->next;
 	}
 	return err;
@@ -3912,7 +4047,7 @@ static void build_fake_ancestor(struct patch *list, const char *filename)
 	discard_index(&result);
 }
 
-static void stat_patch_list(struct patch *patch)
+static void stat_patch_list(struct apply_state *state, struct patch *patch)
 {
 	int files, adds, dels;
 
@@ -3920,13 +4055,14 @@ static void stat_patch_list(struct patch *patch)
 		files++;
 		adds += patch->lines_added;
 		dels += patch->lines_deleted;
-		show_stats(patch);
+		show_stats(state, patch);
 	}
 
 	print_stat_summary(stdout, files, adds, dels);
 }
 
-static void numstat_patch_list(struct patch *patch)
+static void numstat_patch_list(struct apply_state *state,
+			       struct patch *patch)
 {
 	for ( ; patch; patch = patch->next) {
 		const char *name;
@@ -3935,7 +4071,7 @@ static void numstat_patch_list(struct patch *patch)
 			printf("-\t-\t");
 		else
 			printf("%d\t%d\t", patch->lines_added, patch->lines_deleted);
-		write_name_quoted(name, stdout, line_termination);
+		write_name_quoted(name, stdout, state->line_termination);
 	}
 }
 
@@ -4017,49 +4153,53 @@ static void summary_patch_list(struct patch *patch)
 	}
 }
 
-static void patch_stats(struct patch *patch)
+static void patch_stats(struct apply_state *state, struct patch *patch)
 {
 	int lines = patch->lines_added + patch->lines_deleted;
 
-	if (lines > max_change)
-		max_change = lines;
+	if (lines > state->max_change)
+		state->max_change = lines;
 	if (patch->old_name) {
 		int len = quote_c_style(patch->old_name, NULL, NULL, 0);
 		if (!len)
 			len = strlen(patch->old_name);
-		if (len > max_len)
-			max_len = len;
+		if (len > state->max_len)
+			state->max_len = len;
 	}
 	if (patch->new_name) {
 		int len = quote_c_style(patch->new_name, NULL, NULL, 0);
 		if (!len)
 			len = strlen(patch->new_name);
-		if (len > max_len)
-			max_len = len;
+		if (len > state->max_len)
+			state->max_len = len;
 	}
 }
 
-static void remove_file(struct patch *patch, int rmdir_empty)
+static void remove_file(struct apply_state *state, struct patch *patch, int rmdir_empty)
 {
-	if (update_index) {
+	if (state->update_index) {
 		if (remove_file_from_cache(patch->old_name) < 0)
 			die(_("unable to remove %s from index"), patch->old_name);
 	}
-	if (!cached) {
+	if (!state->cached) {
 		if (!remove_or_warn(patch->old_mode, patch->old_name) && rmdir_empty) {
 			remove_path(patch->old_name);
 		}
 	}
 }
 
-static void add_index_file(const char *path, unsigned mode, void *buf, unsigned long size)
+static void add_index_file(struct apply_state *state,
+			   const char *path,
+			   unsigned mode,
+			   void *buf,
+			   unsigned long size)
 {
 	struct stat st;
 	struct cache_entry *ce;
 	int namelen = strlen(path);
 	unsigned ce_size = cache_entry_size(namelen);
 
-	if (!update_index)
+	if (!state->update_index)
 		return;
 
 	ce = xcalloc(1, ce_size);
@@ -4074,7 +4214,7 @@ static void add_index_file(const char *path, unsigned mode, void *buf, unsigned
 		    get_sha1_hex(s, ce->sha1))
 			die(_("corrupt patch for submodule %s"), path);
 	} else {
-		if (!cached) {
+		if (!state->cached) {
 			if (lstat(path, &st) < 0)
 				die_errno(_("unable to stat newly created file '%s'"),
 					  path);
@@ -4126,9 +4266,13 @@ static int try_create_file(const char *path, unsigned int mode, const char *buf,
  * which is true 99% of the time anyway. If they don't,
  * we create them and try again.
  */
-static void create_one_file(char *path, unsigned mode, const char *buf, unsigned long size)
+static void create_one_file(struct apply_state *state,
+			    char *path,
+			    unsigned mode,
+			    const char *buf,
+			    unsigned long size)
 {
-	if (cached)
+	if (state->cached)
 		return;
 	if (!try_create_file(path, mode, buf, size))
 		return;
@@ -4169,13 +4313,14 @@ static void create_one_file(char *path, unsigned mode, const char *buf, unsigned
 	die_errno(_("unable to write file '%s' mode %o"), path, mode);
 }
 
-static void add_conflicted_stages_file(struct patch *patch)
+static void add_conflicted_stages_file(struct apply_state *state,
+				       struct patch *patch)
 {
 	int stage, namelen;
 	unsigned ce_size, mode;
 	struct cache_entry *ce;
 
-	if (!update_index)
+	if (!state->update_index)
 		return;
 	namelen = strlen(patch->new_name);
 	ce_size = cache_entry_size(namelen);
@@ -4196,7 +4341,7 @@ static void add_conflicted_stages_file(struct patch *patch)
 	}
 }
 
-static void create_file(struct patch *patch)
+static void create_file(struct apply_state *state, struct patch *patch)
 {
 	char *path = patch->new_name;
 	unsigned mode = patch->new_mode;
@@ -4205,25 +4350,27 @@ static void create_file(struct patch *patch)
 
 	if (!mode)
 		mode = S_IFREG | 0644;
-	create_one_file(path, mode, buf, size);
+	create_one_file(state, path, mode, buf, size);
 
 	if (patch->conflicted_threeway)
-		add_conflicted_stages_file(patch);
+		add_conflicted_stages_file(state, patch);
 	else
-		add_index_file(path, mode, buf, size);
+		add_index_file(state, path, mode, buf, size);
 }
 
 /* phase zero is to remove, phase one is to create */
-static void write_out_one_result(struct patch *patch, int phase)
+static void write_out_one_result(struct apply_state *state,
+				 struct patch *patch,
+				 int phase)
 {
 	if (patch->is_delete > 0) {
 		if (phase == 0)
-			remove_file(patch, 1);
+			remove_file(state, patch, 1);
 		return;
 	}
 	if (patch->is_new > 0 || patch->is_copy) {
 		if (phase == 1)
-			create_file(patch);
+			create_file(state, patch);
 		return;
 	}
 	/*
@@ -4231,12 +4378,12 @@ static void write_out_one_result(struct patch *patch, int phase)
 	 * thing: remove the old, write the new
 	 */
 	if (phase == 0)
-		remove_file(patch, patch->is_rename);
+		remove_file(state, patch, patch->is_rename);
 	if (phase == 1)
-		create_file(patch);
+		create_file(state, patch);
 }
 
-static int write_out_one_reject(struct patch *patch)
+static int write_out_one_reject(struct apply_state *state, struct patch *patch)
 {
 	FILE *rej;
 	char namebuf[PATH_MAX];
@@ -4251,7 +4398,7 @@ static int write_out_one_reject(struct patch *patch)
 	}
 
 	if (!cnt) {
-		if (apply_verbosely)
+		if (state->apply_verbosely)
 			say_patch_name(stderr,
 				       _("Applied patch %s cleanly."), patch);
 		return 0;
@@ -4307,7 +4454,7 @@ static int write_out_one_reject(struct patch *patch)
 	return -1;
 }
 
-static int write_out_results(struct patch *list)
+static int write_out_results(struct apply_state *state, struct patch *list)
 {
 	int phase;
 	int errs = 0;
@@ -4320,9 +4467,9 @@ static int write_out_results(struct patch *list)
 			if (l->rejected)
 				errs = 1;
 			else {
-				write_out_one_result(l, phase);
+				write_out_one_result(state, l, phase);
 				if (phase == 1) {
-					if (write_out_one_reject(l))
+					if (write_out_one_reject(state, l))
 						errs = 1;
 					if (l->conflicted_threeway) {
 						string_list_append(&cpath, l->new_name);
@@ -4353,14 +4500,17 @@ static struct lock_file lock_file;
 #define INACCURATE_EOF	(1<<0)
 #define RECOUNT		(1<<1)
 
-static int apply_patch(int fd, const char *filename, int options)
+static int apply_patch(struct apply_state *state,
+		       int fd,
+		       const char *filename,
+		       int options)
 {
 	size_t offset;
 	struct strbuf buf = STRBUF_INIT; /* owns the patch text */
 	struct patch *list = NULL, **listp = &list;
 	int skipped_patch = 0;
 
-	patch_input_file = filename;
+	state->patch_input_file = filename;
 	read_patch_file(&buf, fd);
 	offset = 0;
 	while (offset < buf.len) {
@@ -4370,20 +4520,20 @@ static int apply_patch(int fd, const char *filename, int options)
 		patch = xcalloc(1, sizeof(*patch));
 		patch->inaccurate_eof = !!(options & INACCURATE_EOF);
 		patch->recount =  !!(options & RECOUNT);
-		nr = parse_chunk(buf.buf + offset, buf.len - offset, patch);
+		nr = parse_chunk(state, buf.buf + offset, buf.len - offset, patch);
 		if (nr < 0) {
 			free_patch(patch);
 			break;
 		}
-		if (apply_in_reverse)
+		if (state->apply_in_reverse)
 			reverse_patches(patch);
-		if (use_patch(patch)) {
-			patch_stats(patch);
+		if (use_patch(state, patch)) {
+			patch_stats(state, patch);
 			*listp = patch;
 			listp = &patch->next;
 		}
 		else {
-			if (apply_verbosely)
+			if (state->apply_verbosely)
 				say_patch_name(stderr, _("Skipped patch '%s'."), patch);
 			free_patch(patch);
 			skipped_patch++;
@@ -4394,45 +4544,45 @@ static int apply_patch(int fd, const char *filename, int options)
 	if (!list && !skipped_patch)
 		die(_("unrecognized input"));
 
-	if (whitespace_error && (ws_error_action == die_on_ws_error))
-		apply = 0;
+	if (state->whitespace_error && (state->ws_error_action == die_on_ws_error))
+		state->apply = 0;
 
-	update_index = check_index && apply;
-	if (update_index && newfd < 0)
-		newfd = hold_locked_index(&lock_file, 1);
+	state->update_index = state->check_index && state->apply;
+	if (state->update_index && state->newfd < 0)
+		state->newfd = hold_locked_index(state->lock_file, 1);
 
-	if (check_index) {
+	if (state->check_index) {
 		if (read_cache() < 0)
 			die(_("unable to read index file"));
 	}
 
-	if ((check || apply) &&
-	    check_patch_list(list) < 0 &&
-	    !apply_with_reject)
+	if ((state->check || state->apply) &&
+	    check_patch_list(state, list) < 0 &&
+	    !state->apply_with_reject)
 		exit(1);
 
-	if (apply && write_out_results(list)) {
-		if (apply_with_reject)
+	if (state->apply && write_out_results(state, list)) {
+		if (state->apply_with_reject)
 			exit(1);
 		/* with --3way, we still need to write the index out */
 		return 1;
 	}
 
-	if (fake_ancestor)
-		build_fake_ancestor(list, fake_ancestor);
+	if (state->fake_ancestor)
+		build_fake_ancestor(list, state->fake_ancestor);
 
-	if (diffstat)
-		stat_patch_list(list);
+	if (state->diffstat)
+		stat_patch_list(state, list);
 
-	if (numstat)
-		numstat_patch_list(list);
+	if (state->numstat)
+		numstat_patch_list(state, list);
 
-	if (summary)
+	if (state->summary)
 		summary_patch_list(list);
 
 	free_patch_list(list);
 	strbuf_release(&buf);
-	string_list_clear(&fn_table, 0);
+	string_list_clear(&state->fn_table, 0);
 	return 0;
 }
 
@@ -4446,220 +4596,281 @@ static void git_apply_config(void)
 static int option_parse_exclude(const struct option *opt,
 				const char *arg, int unset)
 {
-	add_name_limit(arg, 1);
+	struct apply_state *state = opt->value;
+	add_name_limit(state, arg, 1);
 	return 0;
 }
 
 static int option_parse_include(const struct option *opt,
 				const char *arg, int unset)
 {
-	add_name_limit(arg, 0);
-	has_include = 1;
+	struct apply_state *state = opt->value;
+	add_name_limit(state, arg, 0);
+	state->has_include = 1;
 	return 0;
 }
 
 static int option_parse_p(const struct option *opt,
-			  const char *arg, int unset)
+			  const char *arg,
+			  int unset)
 {
-	p_value = atoi(arg);
-	p_value_known = 1;
+	struct apply_state *state = opt->value;
+	state->p_value = atoi(arg);
+	state->p_value_known = 1;
 	return 0;
 }
 
 static int option_parse_space_change(const struct option *opt,
-			  const char *arg, int unset)
+				     const char *arg, int unset)
 {
+	struct apply_state *state = opt->value;
 	if (unset)
-		ws_ignore_action = ignore_ws_none;
+		state->ws_ignore_action = ignore_ws_none;
 	else
-		ws_ignore_action = ignore_ws_change;
+		state->ws_ignore_action = ignore_ws_change;
 	return 0;
 }
 
 static int option_parse_whitespace(const struct option *opt,
 				   const char *arg, int unset)
 {
-	const char **whitespace_option = opt->value;
-
-	*whitespace_option = arg;
-	parse_whitespace_option(arg);
+	struct apply_state *state = opt->value;
+	state->whitespace_option = arg;
+	parse_whitespace_option(state, arg);
 	return 0;
 }
 
 static int option_parse_directory(const struct option *opt,
 				  const char *arg, int unset)
 {
-	strbuf_reset(&root);
-	strbuf_addstr(&root, arg);
-	strbuf_complete(&root, '/');
+	struct apply_state *state = opt->value;
+	strbuf_reset(&state->root);
+	strbuf_addstr(&state->root, arg);
+	strbuf_complete(&state->root, '/');
 	return 0;
 }
 
-int cmd_apply(int argc, const char **argv, const char *prefix_)
+static void init_apply_state(struct apply_state *state,
+			     const char *prefix,
+			     struct lock_file *lock_file)
+{
+	memset(state, 0, sizeof(*state));
+	state->prefix = prefix;
+	state->prefix_length = state->prefix ? strlen(state->prefix) : 0;
+	state->lock_file = lock_file;
+	state->newfd = -1;
+	state->apply = 1;
+	state->line_termination = '\n';
+	state->p_value = 1;
+	state->p_context = UINT_MAX;
+	state->squelch_whitespace_errors = 5;
+	state->ws_error_action = warn_on_ws_error;
+	state->ws_ignore_action = ignore_ws_none;
+	state->linenr = 1;
+	strbuf_init(&state->root, 0);
+
+	git_apply_config();
+	if (apply_default_whitespace)
+		parse_whitespace_option(state, apply_default_whitespace);
+	if (apply_default_ignorewhitespace)
+		parse_ignorewhitespace_option(state, apply_default_ignorewhitespace);
+}
+
+static void clear_apply_state(struct apply_state *state)
+{
+	string_list_clear(&state->limit_by_name, 0);
+	string_list_clear(&state->symlink_changes, 0);
+	strbuf_release(&state->root);
+
+	/* &state->fn_table is cleared at the end of apply_patch() */
+}
+
+static void check_apply_state(struct apply_state *state, int force_apply)
+{
+	int is_not_gitdir = !startup_info->have_repository;
+
+	if (state->apply_with_reject && state->threeway)
+		die("--reject and --3way cannot be used together.");
+	if (state->cached && state->threeway)
+		die("--cached and --3way cannot be used together.");
+	if (state->threeway) {
+		if (is_not_gitdir)
+			die(_("--3way outside a repository"));
+		state->check_index = 1;
+	}
+	if (state->apply_with_reject)
+		state->apply = state->apply_verbosely = 1;
+	if (!force_apply && (state->diffstat || state->numstat || state->summary || state->check || state->fake_ancestor))
+		state->apply = 0;
+	if (state->check_index && is_not_gitdir)
+		die(_("--index outside a repository"));
+	if (state->cached) {
+		if (is_not_gitdir)
+			die(_("--cached outside a repository"));
+		state->check_index = 1;
+	}
+	if (state->check_index)
+		state->unsafe_paths = 0;
+	if (!state->lock_file)
+		die("BUG: state->lock_file should not be NULL");
+}
+
+static int apply_all_patches(struct apply_state *state,
+			     int argc,
+			     const char **argv,
+			     int options)
 {
 	int i;
 	int errs = 0;
-	int is_not_gitdir = !startup_info->have_repository;
-	int force_apply = 0;
+	int read_stdin = 1;
+
+	for (i = 0; i < argc; i++) {
+		const char *arg = argv[i];
+		int fd;
+
+		if (!strcmp(arg, "-")) {
+			errs |= apply_patch(state, 0, "<stdin>", options);
+			read_stdin = 0;
+			continue;
+		} else if (0 < state->prefix_length)
+			arg = prefix_filename(state->prefix,
+					      state->prefix_length,
+					      arg);
+
+		fd = open(arg, O_RDONLY);
+		if (fd < 0)
+			die_errno(_("can't open patch '%s'"), arg);
+		read_stdin = 0;
+		set_default_whitespace_mode(state);
+		errs |= apply_patch(state, fd, arg, options);
+		close(fd);
+	}
+	set_default_whitespace_mode(state);
+	if (read_stdin)
+		errs |= apply_patch(state, 0, "<stdin>", options);
+
+	if (state->whitespace_error) {
+		if (state->squelch_whitespace_errors &&
+		    state->squelch_whitespace_errors < state->whitespace_error) {
+			int squelched =
+				state->whitespace_error - state->squelch_whitespace_errors;
+			warning(Q_("squelched %d whitespace error",
+				   "squelched %d whitespace errors",
+				   squelched),
+				squelched);
+		}
+		if (state->ws_error_action == die_on_ws_error)
+			die(Q_("%d line adds whitespace errors.",
+			       "%d lines add whitespace errors.",
+			       state->whitespace_error),
+			    state->whitespace_error);
+		if (state->applied_after_fixing_ws && state->apply)
+			warning("%d line%s applied after"
+				" fixing whitespace errors.",
+				state->applied_after_fixing_ws,
+				state->applied_after_fixing_ws == 1 ? "" : "s");
+		else if (state->whitespace_error)
+			warning(Q_("%d line adds whitespace errors.",
+				   "%d lines add whitespace errors.",
+				   state->whitespace_error),
+				state->whitespace_error);
+	}
+
+	if (state->update_index) {
+		if (write_locked_index(&the_index, state->lock_file, COMMIT_LOCK))
+			die(_("Unable to write new index file"));
+		state->newfd = -1;
+	}
+
+	return !!errs;
+}
 
-	const char *whitespace_option = NULL;
+int cmd_apply(int argc, const char **argv, const char *prefix)
+{
+	int force_apply = 0;
+	int options = 0;
+	int ret;
+	struct apply_state state;
 
 	struct option builtin_apply_options[] = {
-		{ OPTION_CALLBACK, 0, "exclude", NULL, N_("path"),
+		{ OPTION_CALLBACK, 0, "exclude", &state, N_("path"),
 			N_("don't apply changes matching the given path"),
 			0, option_parse_exclude },
-		{ OPTION_CALLBACK, 0, "include", NULL, N_("path"),
+		{ OPTION_CALLBACK, 0, "include", &state, N_("path"),
 			N_("apply changes matching the given path"),
 			0, option_parse_include },
-		{ OPTION_CALLBACK, 'p', NULL, NULL, N_("num"),
+		{ OPTION_CALLBACK, 'p', NULL, &state, N_("num"),
 			N_("remove <num> leading slashes from traditional diff paths"),
 			0, option_parse_p },
-		OPT_BOOL(0, "no-add", &no_add,
+		OPT_BOOL(0, "no-add", &state.no_add,
 			N_("ignore additions made by the patch")),
-		OPT_BOOL(0, "stat", &diffstat,
+		OPT_BOOL(0, "stat", &state.diffstat,
 			N_("instead of applying the patch, output diffstat for the input")),
 		OPT_NOOP_NOARG(0, "allow-binary-replacement"),
 		OPT_NOOP_NOARG(0, "binary"),
-		OPT_BOOL(0, "numstat", &numstat,
+		OPT_BOOL(0, "numstat", &state.numstat,
 			N_("show number of added and deleted lines in decimal notation")),
-		OPT_BOOL(0, "summary", &summary,
+		OPT_BOOL(0, "summary", &state.summary,
 			N_("instead of applying the patch, output a summary for the input")),
-		OPT_BOOL(0, "check", &check,
+		OPT_BOOL(0, "check", &state.check,
 			N_("instead of applying the patch, see if the patch is applicable")),
-		OPT_BOOL(0, "index", &check_index,
+		OPT_BOOL(0, "index", &state.check_index,
 			N_("make sure the patch is applicable to the current index")),
-		OPT_BOOL(0, "cached", &cached,
+		OPT_BOOL(0, "cached", &state.cached,
 			N_("apply a patch without touching the working tree")),
-		OPT_BOOL(0, "unsafe-paths", &unsafe_paths,
+		OPT_BOOL(0, "unsafe-paths", &state.unsafe_paths,
 			N_("accept a patch that touches outside the working area")),
 		OPT_BOOL(0, "apply", &force_apply,
 			N_("also apply the patch (use with --stat/--summary/--check)")),
-		OPT_BOOL('3', "3way", &threeway,
+		OPT_BOOL('3', "3way", &state.threeway,
 			 N_( "attempt three-way merge if a patch does not apply")),
-		OPT_FILENAME(0, "build-fake-ancestor", &fake_ancestor,
+		OPT_FILENAME(0, "build-fake-ancestor", &state.fake_ancestor,
 			N_("build a temporary index based on embedded index information")),
 		/* Think twice before adding "--nul" synonym to this */
-		OPT_SET_INT('z', NULL, &line_termination,
+		OPT_SET_INT('z', NULL, &state.line_termination,
 			N_("paths are separated with NUL character"), '\0'),
-		OPT_INTEGER('C', NULL, &p_context,
+		OPT_INTEGER('C', NULL, &state.p_context,
 				N_("ensure at least <n> lines of context match")),
-		{ OPTION_CALLBACK, 0, "whitespace", &whitespace_option, N_("action"),
+		{ OPTION_CALLBACK, 0, "whitespace", &state, N_("action"),
 			N_("detect new or modified lines that have whitespace errors"),
 			0, option_parse_whitespace },
-		{ OPTION_CALLBACK, 0, "ignore-space-change", NULL, NULL,
+		{ OPTION_CALLBACK, 0, "ignore-space-change", &state, NULL,
 			N_("ignore changes in whitespace when finding context"),
 			PARSE_OPT_NOARG, option_parse_space_change },
-		{ OPTION_CALLBACK, 0, "ignore-whitespace", NULL, NULL,
+		{ OPTION_CALLBACK, 0, "ignore-whitespace", &state, NULL,
 			N_("ignore changes in whitespace when finding context"),
 			PARSE_OPT_NOARG, option_parse_space_change },
-		OPT_BOOL('R', "reverse", &apply_in_reverse,
+		OPT_BOOL('R', "reverse", &state.apply_in_reverse,
 			N_("apply the patch in reverse")),
-		OPT_BOOL(0, "unidiff-zero", &unidiff_zero,
+		OPT_BOOL(0, "unidiff-zero", &state.unidiff_zero,
 			N_("don't expect at least one line of context")),
-		OPT_BOOL(0, "reject", &apply_with_reject,
+		OPT_BOOL(0, "reject", &state.apply_with_reject,
 			N_("leave the rejected hunks in corresponding *.rej files")),
-		OPT_BOOL(0, "allow-overlap", &allow_overlap,
+		OPT_BOOL(0, "allow-overlap", &state.allow_overlap,
 			N_("allow overlapping hunks")),
-		OPT__VERBOSE(&apply_verbosely, N_("be verbose")),
+		OPT__VERBOSE(&state.apply_verbosely, N_("be verbose")),
 		OPT_BIT(0, "inaccurate-eof", &options,
 			N_("tolerate incorrectly detected missing new-line at the end of file"),
 			INACCURATE_EOF),
 		OPT_BIT(0, "recount", &options,
 			N_("do not trust the line counts in the hunk headers"),
 			RECOUNT),
-		{ OPTION_CALLBACK, 0, "directory", NULL, N_("root"),
+		{ OPTION_CALLBACK, 0, "directory", &state, N_("root"),
 			N_("prepend <root> to all filenames"),
 			0, option_parse_directory },
 		OPT_END()
 	};
 
-	prefix = prefix_;
-	prefix_length = prefix ? strlen(prefix) : 0;
-	git_apply_config();
-	if (apply_default_whitespace)
-		parse_whitespace_option(apply_default_whitespace);
-	if (apply_default_ignorewhitespace)
-		parse_ignorewhitespace_option(apply_default_ignorewhitespace);
+	init_apply_state(&state, prefix, &lock_file);
 
-	argc = parse_options(argc, argv, prefix, builtin_apply_options,
+	argc = parse_options(argc, argv, state.prefix, builtin_apply_options,
 			apply_usage, 0);
 
-	if (apply_with_reject && threeway)
-		die("--reject and --3way cannot be used together.");
-	if (cached && threeway)
-		die("--cached and --3way cannot be used together.");
-	if (threeway) {
-		if (is_not_gitdir)
-			die(_("--3way outside a repository"));
-		check_index = 1;
-	}
-	if (apply_with_reject)
-		apply = apply_verbosely = 1;
-	if (!force_apply && (diffstat || numstat || summary || check || fake_ancestor))
-		apply = 0;
-	if (check_index && is_not_gitdir)
-		die(_("--index outside a repository"));
-	if (cached) {
-		if (is_not_gitdir)
-			die(_("--cached outside a repository"));
-		check_index = 1;
-	}
-	if (check_index)
-		unsafe_paths = 0;
+	check_apply_state(&state, force_apply);
 
-	for (i = 0; i < argc; i++) {
-		const char *arg = argv[i];
-		int fd;
+	ret = apply_all_patches(&state, argc, argv, options);
 
-		if (!strcmp(arg, "-")) {
-			errs |= apply_patch(0, "<stdin>", options);
-			read_stdin = 0;
-			continue;
-		} else if (0 < prefix_length)
-			arg = prefix_filename(prefix, prefix_length, arg);
+	clear_apply_state(&state);
 
-		fd = open(arg, O_RDONLY);
-		if (fd < 0)
-			die_errno(_("can't open patch '%s'"), arg);
-		read_stdin = 0;
-		set_default_whitespace_mode(whitespace_option);
-		errs |= apply_patch(fd, arg, options);
-		close(fd);
-	}
-	set_default_whitespace_mode(whitespace_option);
-	if (read_stdin)
-		errs |= apply_patch(0, "<stdin>", options);
-	if (whitespace_error) {
-		if (squelch_whitespace_errors &&
-		    squelch_whitespace_errors < whitespace_error) {
-			int squelched =
-				whitespace_error - squelch_whitespace_errors;
-			warning(Q_("squelched %d whitespace error",
-				   "squelched %d whitespace errors",
-				   squelched),
-				squelched);
-		}
-		if (ws_error_action == die_on_ws_error)
-			die(Q_("%d line adds whitespace errors.",
-			       "%d lines add whitespace errors.",
-			       whitespace_error),
-			    whitespace_error);
-		if (applied_after_fixing_ws && apply)
-			warning("%d line%s applied after"
-				" fixing whitespace errors.",
-				applied_after_fixing_ws,
-				applied_after_fixing_ws == 1 ? "" : "s");
-		else if (whitespace_error)
-			warning(Q_("%d line adds whitespace errors.",
-				   "%d lines add whitespace errors.",
-				   whitespace_error),
-				whitespace_error);
-	}
-
-	if (update_index) {
-		if (write_locked_index(&the_index, &lock_file, COMMIT_LOCK))
-			die(_("Unable to write new index file"));
-	}
-
-	return !!errs;
+	return ret;
 }