[PATCH next v2] log_ref_setup: don't return stack-allocated array

[Thomas Rast <trast@student.ethz.ch>]

859c301 (refs: split log_ref_write logic into log_ref_setup,
2010-05-21) refactors the stack allocation of the log_file array into
the new log_ref_setup() function, but passes it back to the caller.

Since the original intent seems to have been to split the work between
log_ref_setup and log_ref_write, make it the caller's responsibility
to allocate the buffer.

Signed-off-by: Thomas Rast <trast@student.ethz.ch>
Reported-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
---

Sorry for the first one, that was completely botched and didn't even
compile.

This one does, and as an added bonus also passes some tests.

 builtin/checkout.c |    4 ++--
 refs.c             |   26 ++++++++++++--------------
 refs.h             |    2 +-
 3 files changed, 15 insertions(+), 17 deletions(-)

diff --git a/builtin/checkout.c b/builtin/checkout.c
index 5107eda..1994be9 100644
--- a/builtin/checkout.c
+++ b/builtin/checkout.c
@@ -496,12 +496,12 @@ static void update_refs_for_switch(struct checkout_opts *opts,
 		if (opts->new_orphan_branch) {
 			if (opts->new_branch_log && !log_all_ref_updates) {
 				int temp;
-				char *log_file;
+				char log_file[PATH_MAX];
 				char *ref_name = mkpath("refs/heads/%s", opts->new_orphan_branch);
 
 				temp = log_all_ref_updates;
 				log_all_ref_updates = 1;
-				if (log_ref_setup(ref_name, &log_file)) {
+				if (log_ref_setup(ref_name, log_file, sizeof(log_file))) {
 					fprintf(stderr, "Can not do reflog for '%s'\n",
 					    opts->new_orphan_branch);
 					log_all_ref_updates = temp;
diff --git a/refs.c b/refs.c
index 3436649..6f486ae 100644
--- a/refs.c
+++ b/refs.c
@@ -1262,43 +1262,41 @@ static int copy_msg(char *buf, const char *msg)
 	return cp - buf;
 }
 
-int log_ref_setup(const char *ref_name, char **log_file)
+int log_ref_setup(const char *ref_name, char *logfile, int bufsize)
 {
 	int logfd, oflags = O_APPEND | O_WRONLY;
-	char logfile[PATH_MAX];
 
-	git_snpath(logfile, sizeof(logfile), "logs/%s", ref_name);
-	*log_file = logfile;
+	git_snpath(logfile, bufsize, "logs/%s", ref_name);
 	if (log_all_ref_updates &&
 	    (!prefixcmp(ref_name, "refs/heads/") ||
 	     !prefixcmp(ref_name, "refs/remotes/") ||
 	     !prefixcmp(ref_name, "refs/notes/") ||
 	     !strcmp(ref_name, "HEAD"))) {
-		if (safe_create_leading_directories(*log_file) < 0)
+		if (safe_create_leading_directories(logfile) < 0)
 			return error("unable to create directory for %s",
-				     *log_file);
+				     logfile);
 		oflags |= O_CREAT;
 	}
 
-	logfd = open(*log_file, oflags, 0666);
+	logfd = open(logfile, oflags, 0666);
 	if (logfd < 0) {
 		if (!(oflags & O_CREAT) && errno == ENOENT)
 			return 0;
 
 		if ((oflags & O_CREAT) && errno == EISDIR) {
-			if (remove_empty_directories(*log_file)) {
+			if (remove_empty_directories(logfile)) {
 				return error("There are still logs under '%s'",
-					     *log_file);
+					     logfile);
 			}
-			logfd = open(*log_file, oflags, 0666);
+			logfd = open(logfile, oflags, 0666);
 		}
 
 		if (logfd < 0)
 			return error("Unable to append to %s: %s",
-				     *log_file, strerror(errno));
+				     logfile, strerror(errno));
 	}
 
-	adjust_shared_perm(*log_file);
+	adjust_shared_perm(logfile);
 	close(logfd);
 	return 0;
 }
@@ -1309,14 +1307,14 @@ static int log_ref_write(const char *ref_name, const unsigned char *old_sha1,
 	int logfd, result, written, oflags = O_APPEND | O_WRONLY;
 	unsigned maxlen, len;
 	int msglen;
-	char *log_file;
+	char log_file[PATH_MAX];
 	char *logrec;
 	const char *committer;
 
 	if (log_all_ref_updates < 0)
 		log_all_ref_updates = !is_bare_repository();
 
-	result = log_ref_setup(ref_name, &log_file);
+	result = log_ref_setup(ref_name, log_file, sizeof(log_file));
 	if (result)
 		return result;
 
diff --git a/refs.h b/refs.h
index 594c9d9..762ce50 100644
--- a/refs.h
+++ b/refs.h
@@ -69,7 +69,7 @@ extern void unlock_ref(struct ref_lock *lock);
 extern int write_ref_sha1(struct ref_lock *lock, const unsigned char *sha1, const char *msg);
 
 /** Setup reflog before using. **/
-int log_ref_setup(const char *ref_name, char **log_file);
+int log_ref_setup(const char *ref_name, char *logfile, int bufsize);
 
 /** Reads log for the value of ref during at_time. **/
 extern int read_ref_at(const char *ref, unsigned long at_time, int cnt, unsigned char *sha1, char **msg, unsigned long *cutoff_time, int *cutoff_tz, int *cutoff_cnt);
-- 
1.7.1.553.ga798e