Merge branch 'jk/strip-suffix'

* jk/strip-suffix:
  prepare_packed_git_one: refactor duplicate-pack check
  verify-pack: use strbuf_strip_suffix
  strbuf: implement strbuf_strip_suffix
  index-pack: use strip_suffix to avoid magic numbers
  use strip_suffix instead of ends_with in simple cases
  replace has_extension with ends_with
  implement ends_with via strip_suffix
  add strip_suffix function
  sha1_file: replace PATH_MAX buffer with strbuf in prepare_packed_git_one()

11 files changed, 101 insertions, 84 deletions

diff --git a/builtin/index-pack.c b/builtin/index-pack.c
index 8b3bd29dbc..fc40411892 100644
--- a/builtin/index-pack.c
+++ b/builtin/index-pack.c
@@ -1506,7 +1506,8 @@ int cmd_index_pack(int argc, const char **argv, const char *prefix)
 	const char *curr_index;
 	const char *index_name = NULL, *pack_name = NULL;
 	const char *keep_name = NULL, *keep_msg = NULL;
-	char *index_name_buf = NULL, *keep_name_buf = NULL;
+	struct strbuf index_name_buf = STRBUF_INIT,
+		      keep_name_buf = STRBUF_INIT;
 	struct pack_idx_entry **idx_objects;
 	struct pack_idx_option opts;
 	unsigned char pack_sha1[20];
@@ -1603,24 +1604,22 @@ int cmd_index_pack(int argc, const char **argv, const char *prefix)
 	if (fix_thin_pack && !from_stdin)
 		die(_("--fix-thin cannot be used without --stdin"));
 	if (!index_name && pack_name) {
-		int len = strlen(pack_name);
-		if (!has_extension(pack_name, ".pack"))
+		size_t len;
+		if (!strip_suffix(pack_name, ".pack", &len))
 			die(_("packfile name '%s' does not end with '.pack'"),
 			    pack_name);
-		index_name_buf = xmalloc(len);
-		memcpy(index_name_buf, pack_name, len - 5);
-		strcpy(index_name_buf + len - 5, ".idx");
-		index_name = index_name_buf;
+		strbuf_add(&index_name_buf, pack_name, len);
+		strbuf_addstr(&index_name_buf, ".idx");
+		index_name = index_name_buf.buf;
 	}
 	if (keep_msg && !keep_name && pack_name) {
-		int len = strlen(pack_name);
-		if (!has_extension(pack_name, ".pack"))
+		size_t len;
+		if (!strip_suffix(pack_name, ".pack", &len))
 			die(_("packfile name '%s' does not end with '.pack'"),
 			    pack_name);
-		keep_name_buf = xmalloc(len);
-		memcpy(keep_name_buf, pack_name, len - 5);
-		strcpy(keep_name_buf + len - 5, ".keep");
-		keep_name = keep_name_buf;
+		strbuf_add(&keep_name_buf, pack_name, len);
+		strbuf_addstr(&keep_name_buf, ".idx");
+		keep_name = keep_name_buf.buf;
 	}
 	if (verify) {
 		if (!index_name)
@@ -1668,8 +1667,8 @@ int cmd_index_pack(int argc, const char **argv, const char *prefix)
 	else
 		close(input_fd);
 	free(objects);
-	free(index_name_buf);
-	free(keep_name_buf);
+	strbuf_release(&index_name_buf);
+	strbuf_release(&keep_name_buf);
 	if (pack_name == NULL)
 		free((void *) curr_pack);
 	if (index_name == NULL)
diff --git a/builtin/remote.c b/builtin/remote.c
index a8efe3da4d..8e1dc39162 100644
--- a/builtin/remote.c
+++ b/builtin/remote.c
@@ -263,16 +263,17 @@ static int config_read_branches(const char *key, const char *value, void *cb)
 		struct string_list_item *item;
 		struct branch_info *info;
 		enum { REMOTE, MERGE, REBASE } type;
+		size_t key_len;
 
 		key += 7;
-		if (ends_with(key, ".remote")) {
-			name = xstrndup(key, strlen(key) - 7);
+		if (strip_suffix(key, ".remote", &key_len)) {
+			name = xmemdupz(key, key_len);
 			type = REMOTE;
-		} else if (ends_with(key, ".merge")) {
-			name = xstrndup(key, strlen(key) - 6);
+		} else if (strip_suffix(key, ".merge", &key_len)) {
+			name = xmemdupz(key, key_len);
 			type = MERGE;
-		} else if (ends_with(key, ".rebase")) {
-			name = xstrndup(key, strlen(key) - 7);
+		} else if (strip_suffix(key, ".rebase", &key_len)) {
+			name = xmemdupz(key, key_len);
 			type = REBASE;
 		} else
 			return 0;
diff --git a/builtin/repack.c b/builtin/repack.c
index ff2216a7aa..a77e743b94 100644
--- a/builtin/repack.c
+++ b/builtin/repack.c
@@ -83,16 +83,15 @@ static void get_non_kept_pack_filenames(struct string_list *fname_list)
 	DIR *dir;
 	struct dirent *e;
 	char *fname;
-	size_t len;
 
 	if (!(dir = opendir(packdir)))
 		return;
 
 	while ((e = readdir(dir)) != NULL) {
-		if (!ends_with(e->d_name, ".pack"))
+		size_t len;
+		if (!strip_suffix(e->d_name, ".pack", &len))
 			continue;
 
-		len = strlen(e->d_name) - strlen(".pack");
 		fname = xmemdupz(e->d_name, len);
 
 		if (!file_exists(mkpath("%s/%s.keep", packdir, fname)))
diff --git a/builtin/verify-pack.c b/builtin/verify-pack.c
index 66cd2df0f8..972579f33c 100644
--- a/builtin/verify-pack.c
+++ b/builtin/verify-pack.c
@@ -27,10 +27,9 @@ static int verify_one_pack(const char *path, unsigned int flags)
 	 * normalize these forms to "foo.pack" for "index-pack --verify".
 	 */
 	strbuf_addstr(&arg, path);
-	if (has_extension(arg.buf, ".idx"))
-		strbuf_splice(&arg, arg.len - 3, 3, "pack", 4);
-	else if (!has_extension(arg.buf, ".pack"))
-		strbuf_add(&arg, ".pack", 5);
+	if (strbuf_strip_suffix(&arg, ".idx") ||
+	    !ends_with(arg.buf, ".pack"))
+		strbuf_addstr(&arg, ".pack");
 	argv[2] = arg.buf;
 
 	memset(&index_pack, 0, sizeof(index_pack));
diff --git a/connected.c b/connected.c
index be0253e21b..dae9c9972e 100644
--- a/connected.c
+++ b/connected.c
@@ -31,6 +31,7 @@ static int check_everything_connected_real(sha1_iterate_fn fn,
 	unsigned char sha1[20];
 	int err = 0, ac = 0;
 	struct packed_git *new_pack = NULL;
+	size_t base_len;
 
 	if (fn(cb_data, sha1))
 		return err;
@@ -38,10 +39,9 @@ static int check_everything_connected_real(sha1_iterate_fn fn,
 	if (transport && transport->smart_options &&
 	    transport->smart_options->self_contained_and_connected &&
 	    transport->pack_lockfile &&
-	    ends_with(transport->pack_lockfile, ".keep")) {
+	    strip_suffix(transport->pack_lockfile, ".keep", &base_len)) {
 		struct strbuf idx_file = STRBUF_INIT;
-		strbuf_addstr(&idx_file, transport->pack_lockfile);
-		strbuf_setlen(&idx_file, idx_file.len - 5); /* ".keep" */
+		strbuf_add(&idx_file, transport->pack_lockfile, base_len);
 		strbuf_addstr(&idx_file, ".idx");
 		new_pack = add_packed_git(idx_file.buf, idx_file.len, 1);
 		strbuf_release(&idx_file);
diff --git a/git-compat-util.h b/git-compat-util.h
index 9de3180710..0b53c9a4af 100644
--- a/git-compat-util.h
+++ b/git-compat-util.h
@@ -347,7 +347,6 @@ extern void set_error_routine(void (*routine)(const char *err, va_list params));
 extern void set_die_is_recursing_routine(int (*routine)(void));
 
 extern int starts_with(const char *str, const char *prefix);
-extern int ends_with(const char *str, const char *suffix);
 
 /*
  * If the string "str" begins with the string found in "prefix", return 1.
@@ -377,6 +376,39 @@ static inline int skip_prefix(const char *str, const char *prefix,
 	return 0;
 }
 
+/*
+ * If buf ends with suffix, return 1 and subtract the length of the suffix
+ * from *len. Otherwise, return 0 and leave *len untouched.
+ */
+static inline int strip_suffix_mem(const char *buf, size_t *len,
+				   const char *suffix)
+{
+	size_t suflen = strlen(suffix);
+	if (*len < suflen || memcmp(buf + (*len - suflen), suffix, suflen))
+		return 0;
+	*len -= suflen;
+	return 1;
+}
+
+/*
+ * If str ends with suffix, return 1 and set *len to the size of the string
+ * without the suffix. Otherwise, return 0 and set *len to the size of the
+ * string.
+ *
+ * Note that we do _not_ NUL-terminate str to the new length.
+ */
+static inline int strip_suffix(const char *str, const char *suffix, size_t *len)
+{
+	*len = strlen(str);
+	return strip_suffix_mem(str, len, suffix);
+}
+
+static inline int ends_with(const char *str, const char *suffix)
+{
+	size_t len;
+	return strip_suffix(str, suffix, &len);
+}
+
 #if defined(NO_MMAP) || defined(USE_WIN32_MMAP)
 
 #ifndef PROT_READ
@@ -581,13 +613,6 @@ static inline size_t xsize_t(off_t len)
 	return (size_t)len;
 }
 
-static inline int has_extension(const char *filename, const char *ext)
-{
-	size_t len = strlen(filename);
-	size_t extlen = strlen(ext);
-	return len > extlen && !memcmp(filename + len - extlen, ext, extlen);
-}
-
 /* in ctype.c, for kwset users */
 extern const char tolower_trans_tbl[256];
 
diff --git a/help.c b/help.c
index f31f29ac42..7af65e205e 100644
--- a/help.c
+++ b/help.c
@@ -144,7 +144,7 @@ static void list_commands_in_dir(struct cmdnames *cmds,
 
 	while ((de = readdir(dir)) != NULL) {
 		const char *ent;
-		int entlen;
+		size_t entlen;
 
 		if (!skip_prefix(de->d_name, prefix, &ent))
 			continue;
@@ -155,8 +155,7 @@ static void list_commands_in_dir(struct cmdnames *cmds,
 			continue;
 
 		entlen = strlen(ent);
-		if (has_extension(ent, ".exe"))
-			entlen -= 4;
+		strip_suffix(ent, ".exe", &entlen);
 
 		add_cmdname(cmds, ent, entlen);
 	}
diff --git a/refs.c b/refs.c
index 82e4842a36..061d233e4b 100644
--- a/refs.c
+++ b/refs.c
@@ -1361,7 +1361,7 @@ static void read_loose_refs(const char *dirname, struct ref_dir *dir)
 
 		if (de->d_name[0] == '.')
 			continue;
-		if (has_extension(de->d_name, ".lock"))
+		if (ends_with(de->d_name, ".lock"))
 			continue;
 		strbuf_addstr(&refname, de->d_name);
 		refdir = *refs->name
@@ -3432,7 +3432,7 @@ static int do_for_each_reflog(struct strbuf *name, each_ref_fn fn, void *cb_data
 
 		if (de->d_name[0] == '.')
 			continue;
-		if (has_extension(de->d_name, ".lock"))
+		if (ends_with(de->d_name, ".lock"))
 			continue;
 		strbuf_addstr(name, de->d_name);
 		if (stat(git_path("logs/%s", name->buf), &st) < 0) {
diff --git a/sha1_file.c b/sha1_file.c
index a38854ce55..4127ae138d 100644
--- a/sha1_file.c
+++ b/sha1_file.c
@@ -1178,48 +1178,42 @@ static void report_pack_garbage(struct string_list *list)
 
 static void prepare_packed_git_one(char *objdir, int local)
 {
-	/* Ensure that this buffer is large enough so that we can
-	   append "/pack/" without clobbering the stack even if
-	   strlen(objdir) were PATH_MAX.  */
-	char path[PATH_MAX + 1 + 4 + 1 + 1];
-	int len;
+	struct strbuf path = STRBUF_INIT;
+	size_t dirnamelen;
 	DIR *dir;
 	struct dirent *de;
 	struct string_list garbage = STRING_LIST_INIT_DUP;
 
-	sprintf(path, "%s/pack", objdir);
-	len = strlen(path);
-	dir = opendir(path);
+	strbuf_addstr(&path, objdir);
+	strbuf_addstr(&path, "/pack");
+	dir = opendir(path.buf);
 	if (!dir) {
 		if (errno != ENOENT)
 			error("unable to open object pack directory: %s: %s",
-			      path, strerror(errno));
+			      path.buf, strerror(errno));
+		strbuf_release(&path);
 		return;
 	}
-	path[len++] = '/';
+	strbuf_addch(&path, '/');
+	dirnamelen = path.len;
 	while ((de = readdir(dir)) != NULL) {
-		int namelen = strlen(de->d_name);
 		struct packed_git *p;
-
-		if (len + namelen + 1 > sizeof(path)) {
-			if (report_garbage) {
-				struct strbuf sb = STRBUF_INIT;
-				strbuf_addf(&sb, "%.*s/%s", len - 1, path, de->d_name);
-				report_garbage("path too long", sb.buf);
-				strbuf_release(&sb);
-			}
-			continue;
-		}
+		size_t base_len;
 
 		if (is_dot_or_dotdot(de->d_name))
 			continue;
 
-		strcpy(path + len, de->d_name);
+		strbuf_setlen(&path, dirnamelen);
+		strbuf_addstr(&path, de->d_name);
 
-		if (has_extension(de->d_name, ".idx")) {
+		base_len = path.len;
+		if (strip_suffix_mem(path.buf, &base_len, ".idx")) {
 			/* Don't reopen a pack we already have. */
 			for (p = packed_git; p; p = p->next) {
-				if (!memcmp(path, p->pack_name, len + namelen - 4))
+				size_t len;
+				if (strip_suffix(p->pack_name, ".pack", &len) &&
+				    len == base_len &&
+				    !memcmp(p->pack_name, path.buf, len))
 					break;
 			}
 			if (p == NULL &&
@@ -1227,24 +1221,25 @@ static void prepare_packed_git_one(char *objdir, int local)
 			     * See if it really is a valid .idx file with
 			     * corresponding .pack file that we can map.
 			     */
-			    (p = add_packed_git(path, len + namelen, local)) != NULL)
+			    (p = add_packed_git(path.buf, path.len, local)) != NULL)
 				install_packed_git(p);
 		}
 
 		if (!report_garbage)
 			continue;
 
-		if (has_extension(de->d_name, ".idx") ||
-		    has_extension(de->d_name, ".pack") ||
-		    has_extension(de->d_name, ".bitmap") ||
-		    has_extension(de->d_name, ".keep"))
-			string_list_append(&garbage, path);
+		if (ends_with(de->d_name, ".idx") ||
+		    ends_with(de->d_name, ".pack") ||
+		    ends_with(de->d_name, ".bitmap") ||
+		    ends_with(de->d_name, ".keep"))
+			string_list_append(&garbage, path.buf);
 		else
-			report_garbage("garbage found", path);
+			report_garbage("garbage found", path.buf);
 	}
 	closedir(dir);
 	report_pack_garbage(&garbage);
 	string_list_clear(&garbage, 0);
+	strbuf_release(&path);
 }
 
 static int sort_pack(const void *a_, const void *b_)
diff --git a/strbuf.c b/strbuf.c
index 12c78656ca..33018d847f 100644
--- a/strbuf.c
+++ b/strbuf.c
@@ -11,15 +11,6 @@ int starts_with(const char *str, const char *prefix)
 			return 0;
 }
 
-int ends_with(const char *str, const char *suffix)
-{
-	int len = strlen(str), suflen = strlen(suffix);
-	if (len < suflen)
-		return 0;
-	else
-		return !strcmp(str + len - suflen, suffix);
-}
-
 /*
  * Used as the default ->buf value, so that people can always assume
  * buf is non NULL and ->buf is NUL terminated even for a freshly
diff --git a/strbuf.h b/strbuf.h
index a594c24b2b..a7c0192e9e 100644
--- a/strbuf.h
+++ b/strbuf.h
@@ -49,6 +49,15 @@ extern int strbuf_reencode(struct strbuf *sb, const char *from, const char *to);
 extern void strbuf_tolower(struct strbuf *sb);
 extern int strbuf_cmp(const struct strbuf *, const struct strbuf *);
 
+static inline int strbuf_strip_suffix(struct strbuf *sb, const char *suffix)
+{
+	if (strip_suffix_mem(sb->buf, &sb->len, suffix)) {
+		strbuf_setlen(sb, sb->len);
+		return 1;
+	} else
+		return 0;
+}
+
 /*
  * Split str (of length slen) at the specified terminator character.
  * Return a null-terminated array of pointers to strbuf objects