Merge branch 'jk/diff-blob'

The result from "git diff" that compares two blobs, e.g. "git diff
$commit1:$path $commit2:$path", used to be shown with the full
object name as given on the command line, but it is more natural to
use the $path in the output and use it to look up .gitattributes.

* jk/diff-blob:
  diff: use blob path for blob/file diffs
  diff: use pending "path" if it is available
  diff: use the word "path" instead of "name" for blobs
  diff: pass whole pending entry in blobinfo
  handle_revision_arg: record paths for pending objects
  handle_revision_arg: record modes for "a..b" endpoints
  t4063: add tests of direct blob diffs
  get_sha1_with_context: dynamically allocate oc->path
  get_sha1_with_context: always initialize oc->symlink_path
  sha1_name: consistently refer to object_context as "oc"
  handle_revision_arg: add handle_dotdot() helper
  handle_revision_arg: hoist ".." check out of range parsing
  handle_revision_arg: stop using "dotdot" as a generic pointer
  handle_revision_arg: simplify commit reference lookups
  handle_revision_arg: reset "dotdot" consistently

1 files changed, 139 insertions, 104 deletions

diff --git a/revision.c b/revision.c
index b023945309..3680a43a6e 100644
--- a/revision.c
+++ b/revision.c
@@ -1429,134 +1429,168 @@ static void prepare_show_merge(struct rev_info *revs)
 	revs->limited = 1;
 }
 
+static int dotdot_missing(const char *arg, char *dotdot,
+			  struct rev_info *revs, int symmetric)
+{
+	if (revs->ignore_missing)
+		return 0;
+	/* de-munge so we report the full argument */
+	*dotdot = '.';
+	die(symmetric
+	    ? "Invalid symmetric difference expression %s"
+	    : "Invalid revision range %s", arg);
+}
+
+static int handle_dotdot_1(const char *arg, char *dotdot,
+			   struct rev_info *revs, int flags,
+			   int cant_be_filename,
+			   struct object_context *a_oc,
+			   struct object_context *b_oc)
+{
+	const char *a_name, *b_name;
+	struct object_id a_oid, b_oid;
+	struct object *a_obj, *b_obj;
+	unsigned int a_flags, b_flags;
+	int symmetric = 0;
+	unsigned int flags_exclude = flags ^ (UNINTERESTING | BOTTOM);
+	unsigned int oc_flags = GET_SHA1_COMMITTISH | GET_SHA1_RECORD_PATH;
+
+	a_name = arg;
+	if (!*a_name)
+		a_name = "HEAD";
+
+	b_name = dotdot + 2;
+	if (*b_name == '.') {
+		symmetric = 1;
+		b_name++;
+	}
+	if (!*b_name)
+		b_name = "HEAD";
+
+	if (get_sha1_with_context(a_name, oc_flags, a_oid.hash, a_oc) ||
+	    get_sha1_with_context(b_name, oc_flags, b_oid.hash, b_oc))
+		return -1;
+
+	if (!cant_be_filename) {
+		*dotdot = '.';
+		verify_non_filename(revs->prefix, arg);
+		*dotdot = '\0';
+	}
+
+	a_obj = parse_object(&a_oid);
+	b_obj = parse_object(&b_oid);
+	if (!a_obj || !b_obj)
+		return dotdot_missing(arg, dotdot, revs, symmetric);
+
+	if (!symmetric) {
+		/* just A..B */
+		b_flags = flags;
+		a_flags = flags_exclude;
+	} else {
+		/* A...B -- find merge bases between the two */
+		struct commit *a, *b;
+		struct commit_list *exclude;
+
+		a = lookup_commit_reference(&a_obj->oid);
+		b = lookup_commit_reference(&b_obj->oid);
+		if (!a || !b)
+			return dotdot_missing(arg, dotdot, revs, symmetric);
+
+		exclude = get_merge_bases(a, b);
+		add_rev_cmdline_list(revs, exclude, REV_CMD_MERGE_BASE,
+				     flags_exclude);
+		add_pending_commit_list(revs, exclude, flags_exclude);
+		free_commit_list(exclude);
+
+		b_flags = flags;
+		a_flags = flags | SYMMETRIC_LEFT;
+	}
+
+	a_obj->flags |= a_flags;
+	b_obj->flags |= b_flags;
+	add_rev_cmdline(revs, a_obj, a_name, REV_CMD_LEFT, a_flags);
+	add_rev_cmdline(revs, b_obj, b_name, REV_CMD_RIGHT, b_flags);
+	add_pending_object_with_path(revs, a_obj, a_name, a_oc->mode, a_oc->path);
+	add_pending_object_with_path(revs, b_obj, b_name, b_oc->mode, b_oc->path);
+	return 0;
+}
+
+static int handle_dotdot(const char *arg,
+			 struct rev_info *revs, int flags,
+			 int cant_be_filename)
+{
+	struct object_context a_oc, b_oc;
+	char *dotdot = strstr(arg, "..");
+	int ret;
+
+	if (!dotdot)
+		return -1;
+
+	memset(&a_oc, 0, sizeof(a_oc));
+	memset(&b_oc, 0, sizeof(b_oc));
+
+	*dotdot = '\0';
+	ret = handle_dotdot_1(arg, dotdot, revs, flags, cant_be_filename,
+			      &a_oc, &b_oc);
+	*dotdot = '.';
+
+	free(a_oc.path);
+	free(b_oc.path);
+
+	return ret;
+}
+
 int handle_revision_arg(const char *arg_, struct rev_info *revs, int flags, unsigned revarg_opt)
 {
 	struct object_context oc;
-	char *dotdot;
+	char *mark;
 	struct object *object;
 	struct object_id oid;
 	int local_flags;
 	const char *arg = arg_;
 	int cant_be_filename = revarg_opt & REVARG_CANNOT_BE_FILENAME;
-	unsigned get_sha1_flags = 0;
+	unsigned get_sha1_flags = GET_SHA1_RECORD_PATH;
 
 	flags = flags & UNINTERESTING ? flags | BOTTOM : flags & ~BOTTOM;
 
-	dotdot = strstr(arg, "..");
-	if (dotdot) {
-		struct object_id from_oid;
-		const char *next = dotdot + 2;
-		const char *this = arg;
-		int symmetric = *next == '.';
-		unsigned int flags_exclude = flags ^ (UNINTERESTING | BOTTOM);
-		static const char head_by_default[] = "HEAD";
-		unsigned int a_flags;
-
-		*dotdot = 0;
-		next += symmetric;
-
-		if (!*next)
-			next = head_by_default;
-		if (dotdot == arg)
-			this = head_by_default;
-		if (this == head_by_default && next == head_by_default &&
-		    !symmetric) {
-			/*
-			 * Just ".."?  That is not a range but the
-			 * pathspec for the parent directory.
-			 */
-			if (!cant_be_filename) {
-				*dotdot = '.';
-				return -1;
-			}
-		}
-		if (!get_sha1_committish(this, from_oid.hash) &&
-		    !get_sha1_committish(next, oid.hash)) {
-			struct object *a_obj, *b_obj;
-
-			if (!cant_be_filename) {
-				*dotdot = '.';
-				verify_non_filename(revs->prefix, arg);
-			}
-
-			a_obj = parse_object(&from_oid);
-			b_obj = parse_object(&oid);
-			if (!a_obj || !b_obj) {
-			missing:
-				if (revs->ignore_missing)
-					return 0;
-				die(symmetric
-				    ? "Invalid symmetric difference expression %s"
-				    : "Invalid revision range %s", arg);
-			}
-
-			if (!symmetric) {
-				/* just A..B */
-				a_flags = flags_exclude;
-			} else {
-				/* A...B -- find merge bases between the two */
-				struct commit *a, *b;
-				struct commit_list *exclude;
-
-				a = (a_obj->type == OBJ_COMMIT
-				     ? (struct commit *)a_obj
-				     : lookup_commit_reference(&a_obj->oid));
-				b = (b_obj->type == OBJ_COMMIT
-				     ? (struct commit *)b_obj
-				     : lookup_commit_reference(&b_obj->oid));
-				if (!a || !b)
-					goto missing;
-				exclude = get_merge_bases(a, b);
-				add_rev_cmdline_list(revs, exclude,
-						     REV_CMD_MERGE_BASE,
-						     flags_exclude);
-				add_pending_commit_list(revs, exclude,
-							flags_exclude);
-				free_commit_list(exclude);
-
-				a_flags = flags | SYMMETRIC_LEFT;
-			}
-
-			a_obj->flags |= a_flags;
-			b_obj->flags |= flags;
-			add_rev_cmdline(revs, a_obj, this,
-					REV_CMD_LEFT, a_flags);
-			add_rev_cmdline(revs, b_obj, next,
-					REV_CMD_RIGHT, flags);
-			add_pending_object(revs, a_obj, this);
-			add_pending_object(revs, b_obj, next);
-			return 0;
-		}
-		*dotdot = '.';
+	if (!cant_be_filename && !strcmp(arg, "..")) {
+		/*
+		 * Just ".."?  That is not a range but the
+		 * pathspec for the parent directory.
+		 */
+		return -1;
 	}
 
-	dotdot = strstr(arg, "^@");
-	if (dotdot && !dotdot[2]) {
-		*dotdot = 0;
+	if (!handle_dotdot(arg, revs, flags, revarg_opt))
+		return 0;
+
+	mark = strstr(arg, "^@");
+	if (mark && !mark[2]) {
+		*mark = 0;
 		if (add_parents_only(revs, arg, flags, 0))
 			return 0;
-		*dotdot = '^';
+		*mark = '^';
 	}
-	dotdot = strstr(arg, "^!");
-	if (dotdot && !dotdot[2]) {
-		*dotdot = 0;
+	mark = strstr(arg, "^!");
+	if (mark && !mark[2]) {
+		*mark = 0;
 		if (!add_parents_only(revs, arg, flags ^ (UNINTERESTING | BOTTOM), 0))
-			*dotdot = '^';
+			*mark = '^';
 	}
-	dotdot = strstr(arg, "^-");
-	if (dotdot) {
+	mark = strstr(arg, "^-");
+	if (mark) {
 		int exclude_parent = 1;
 
-		if (dotdot[2]) {
+		if (mark[2]) {
 			char *end;
-			exclude_parent = strtoul(dotdot + 2, &end, 10);
+			exclude_parent = strtoul(mark + 2, &end, 10);
 			if (*end != '\0' || !exclude_parent)
 				return -1;
 		}
 
-		*dotdot = 0;
+		*mark = 0;
 		if (!add_parents_only(revs, arg, flags ^ (UNINTERESTING | BOTTOM), exclude_parent))
-			*dotdot = '^';
+			*mark = '^';
 	}
 
 	local_flags = 0;
@@ -1566,7 +1600,7 @@ int handle_revision_arg(const char *arg_, struct rev_info *revs, int flags, unsi
 	}
 
 	if (revarg_opt & REVARG_COMMITTISH)
-		get_sha1_flags = GET_SHA1_COMMITTISH;
+		get_sha1_flags |= GET_SHA1_COMMITTISH;
 
 	if (get_sha1_with_context(arg, get_sha1_flags, oid.hash, &oc))
 		return revs->ignore_missing ? 0 : -1;
@@ -1574,7 +1608,8 @@ int handle_revision_arg(const char *arg_, struct rev_info *revs, int flags, unsi
 		verify_non_filename(revs->prefix, arg);
 	object = get_reference(revs, arg, &oid, flags ^ local_flags);
 	add_rev_cmdline(revs, object, arg_, REV_CMD_REV, flags ^ local_flags);
-	add_pending_object_with_mode(revs, object, arg, oc.mode);
+	add_pending_object_with_path(revs, object, arg, oc.mode, oc.path);
+	free(oc.path);
 	return 0;
 }