threads / patch / 12355

patchTeach git-describe to verify annotated tag names before output

Subject: [PATCH] Teach git-describe to verify annotated tag names before output

## tl;dr

2 messages between Feb 28, 2008 and Mar 3, 2008. Diffs are folded; open one to read it.

replies: 1people: 2as markdown or json

Shawn O. Pearce· Feb 28, 2008, 06:22 UTC · lore

If an annotated tag describes a commit we want to favor the name listed in the body of the tag, rather than whatever name it has been stored under locally. By doing so it is easier to converse about tags with others, even if the tags happen to be fetched to a different name than it was given by its creator.

To avoid confusion when a tag is stored under a different name (and thus is not readable via git-rev-parse --verify, etc.) we show a warning message if the name of the tag does not match the ref we found it under and if that tag was also selected for output. For example:

  $ git tag -a -m "i am a test" testtag
  $ mv .git/refs/tags/testtag .git/refs/tags/bobbytag
  $ ./git-describe HEAD
  warning: tag 'testtag' is really 'bobbytag' here
  testtag
  $ git tag -d testtag
  error: tag 'testtag' not found.
  $ git tag -d bobbytag
  Deleted tag 'bobbytag'
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
---
 builtin-describe.c |   38 ++++++++++++++++++++++++++++++--------
 1 files changed, 30 insertions(+), 8 deletions(-)
Show changes to builtin-describe.c +30 −8
diff --git a/builtin-describe.c b/builtin-describe.c
index 05e309f..08d1850 100644
--- a/builtin-describe.c
+++ b/builtin-describe.c
@@ -22,7 +22,9 @@ static int max_candidates = 10;
 const char *pattern = NULL;
 
 struct commit_name {
+	struct tag *tag;
 	int prio; /* annotated tag = 2, tag = 1, head = 0 */
+	unsigned char sha1[20];
 	char path[FLEX_ARRAY]; /* more */
 };
 static const char *prio_names[] = {
@@ -31,14 +33,17 @@ static const char *prio_names[] = {
 
 static void add_to_known_names(const char *path,
 			       struct commit *commit,
-			       int prio)
+			       int prio,
+			       const unsigned char *sha1)
 {
 	struct commit_name *e = commit->util;
 	if (!e || e->prio < prio) {
 		size_t len = strlen(path)+1;
 		free(e);
 		e = xmalloc(sizeof(struct commit_name) + len);
+		e->tag = NULL;
 		e->prio = prio;
+		hashcpy(e->sha1, sha1);
 		memcpy(e->path, path, len);
 		commit->util = e;
 	}
@@ -89,7 +94,7 @@ static int get_name(const char *path, const unsigned char *sha1, int flag, void
 		if (!tags && prio < 2)
 			return 0;
 	}
-	add_to_known_names(all ? path + 5 : path + 10, commit, prio);
+	add_to_known_names(all ? path + 5 : path + 10, commit, prio, sha1);
 	return 0;
 }
 
@@ -146,6 +151,22 @@ static unsigned long finish_depth_computation(
 	return seen_commits;
 }
 
+static void display_name(struct commit_name *n)
+{
+	if (n->prio == 2 && !n->tag) {
+		n->tag = lookup_tag(n->sha1);
+		if (!n->tag || !n->tag->tag)
+			die("annotated tag %s not available", n->path);
+		if (strcmp(n->tag->tag, n->path))
+			warning("tag '%s' is really '%s' here", n->tag->tag, n->path);
+	}
+
+	if (n->tag)
+		printf("%s", n->tag->tag);
+	else
+		printf("%s", n->path);
+}
+
 static void describe(const char *arg, int last_one)
 {
 	unsigned char sha1[20];
@@ -170,7 +191,8 @@ static void describe(const char *arg, int last_one)
 
 	n = cmit->util;
 	if (n) {
-		printf("%s\n", n->path);
+		display_name(n);
+		printf("\n");
 		return;
 	}
 
@@ -252,12 +274,12 @@ static void describe(const char *arg, int last_one)
 				sha1_to_hex(gave_up_on->object.sha1));
 		}
 	}
-	if (abbrev == 0)
-		printf("%s\n", all_matches[0].name->path );
-	else
-		printf("%s-%d-g%s\n", all_matches[0].name->path,
-		       all_matches[0].depth,
+
+	display_name(all_matches[0].name);
+	if (abbrev)
+		printf("-%d-g%s", all_matches[0].depth,
 		       find_unique_abbrev(cmit->object.sha1, abbrev));
+	printf("\n");
 
 	if (!last_one)
 		clear_commit_marks(cmit, -1);
-- 
1.5.4.3.393.g5540
Junio C Hamano· Mar 3, 2008, 17:13 UTC · re: Shawn O. Pearce · lore

git-describe: use tags found in packed-refs correctly

When your refs are packed, "git-describe" can find the tag that is the best match without ever parsing the tag itself. But lookup_tag() in display_name() says "I've never seen it", creates an empty shell, and returns it. We need to make sure that we actually have parsed the tag data into it.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 builtin-describe.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
Show changes to builtin-describe.c +1 −1
diff --git a/builtin-describe.c b/builtin-describe.c
index 2f1e7ba..c549d36 100644
--- a/builtin-describe.c
+++ b/builtin-describe.c
@@ -156,7 +156,7 @@ static void display_name(struct commit_name *n)
 {
 	if (n->prio == 2 && !n->tag) {
 		n->tag = lookup_tag(n->sha1);
-		if (!n->tag || !n->tag->tag)
+		if (parse_tag(n->tag) || !n->tag || !n->tag->tag)
 			die("annotated tag %s not available", n->path);
 		if (strcmp(n->tag->tag, n->path))
 			warning("tag '%s' is really '%s' here", n->tag->tag, n->path);

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