Merge branch 'jk/read-commit-buffer-data-after-free'

Clarify the ownership rule for commit->buffer field, which some
callers incorrectly accessed without making sure it is populated.

* jk/read-commit-buffer-data-after-free:
  logmsg_reencode: lazily load missing commit buffers
  logmsg_reencode: never return NULL
  commit: drop useless xstrdup of commit message

2 files changed, 6 insertions, 30 deletions

diff --git a/builtin/blame.c b/builtin/blame.c
index b431ba3209..86100e9662 100644
--- a/builtin/blame.c
+++ b/builtin/blame.c
@@ -1420,32 +1420,18 @@ static void get_commit_info(struct commit *commit,
 {
 	int len;
 	const char *subject, *encoding;
-	char *reencoded, *message;
+	char *message;
 
 	commit_info_init(ret);
 
-	/*
-	 * We've operated without save_commit_buffer, so
-	 * we now need to populate them for output.
-	 */
-	if (!commit->buffer) {
-		enum object_type type;
-		unsigned long size;
-		commit->buffer =
-			read_sha1_file(commit->object.sha1, &type, &size);
-		if (!commit->buffer)
-			die("Cannot read commit %s",
-			    sha1_to_hex(commit->object.sha1));
-	}
 	encoding = get_log_output_encoding();
-	reencoded = logmsg_reencode(commit, encoding);
-	message   = reencoded ? reencoded : commit->buffer;
+	message = logmsg_reencode(commit, encoding);
 	get_ac_line(message, "\nauthor ",
 		    &ret->author, &ret->author_mail,
 		    &ret->author_time, &ret->author_tz);
 
 	if (!detailed) {
-		free(reencoded);
+		logmsg_free(message, commit);
 		return;
 	}
 
@@ -1459,7 +1445,7 @@ static void get_commit_info(struct commit *commit,
 	else
 		strbuf_addf(&ret->summary, "(%s)", sha1_to_hex(commit->object.sha1));
 
-	free(reencoded);
+	logmsg_free(message, commit);
 }
 
 /*
diff --git a/builtin/commit.c b/builtin/commit.c
index 6c95fa76d8..1a0e5f14a3 100644
--- a/builtin/commit.c
+++ b/builtin/commit.c
@@ -946,24 +946,14 @@ static void handle_untracked_files_arg(struct wt_status *s)
 
 static const char *read_commit_message(const char *name)
 {
-	const char *out_enc, *out;
+	const char *out_enc;
 	struct commit *commit;
 
 	commit = lookup_commit_reference_by_name(name);
 	if (!commit)
 		die(_("could not lookup commit %s"), name);
 	out_enc = get_commit_output_encoding();
-	out = logmsg_reencode(commit, out_enc);
-
-	/*
-	 * If we failed to reencode the buffer, just copy it
-	 * byte for byte so the user can try to fix it up.
-	 * This also handles the case where input and output
-	 * encodings are identical.
-	 */
-	if (out == NULL)
-		out = xstrdup(commit->buffer);
-	return out;
+	return logmsg_reencode(commit, out_enc);
 }
 
 static int parse_and_validate_options(int argc, const char *argv[],