From d66da478f26df3114af1177fa5614035439178ed Mon Sep 17 00:00:00 2001
From: Michael Haggerty <mhagger@alum.mit.edu>
Date: Tue, 10 Apr 2012 07:30:17 +0200
Subject: [PATCH] repack_without_ref(): reimplement using
 do_for_each_ref_in_array()

It costs a bit of boilerplate, but it means that the function can be
ignorant of how cached refs are stored.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 refs.c | 94 +++++++++++++++++++++++++++++++++++++---------------------
 1 file changed, 61 insertions(+), 33 deletions(-)

diff --git a/refs.c b/refs.c
index 05a5dc815b..d40ab63e91 100644
--- a/refs.c
+++ b/refs.c
@@ -333,6 +333,30 @@ static int do_for_each_ref_in_arrays(struct ref_array *array1,
 	return 0;
 }
 
+/*
+ * Return true iff refname1 and refname2 conflict with each other.
+ * Two reference names conflict if one of them exactly matches the
+ * leading components of the other; e.g., "foo/bar" conflicts with
+ * both "foo" and with "foo/bar/baz" but not with "foo/bar" or
+ * "foo/barbados".
+ */
+static int names_conflict(const char *refname1, const char *refname2)
+{
+	int len1 = strlen(refname1);
+	int len2 = strlen(refname2);
+	int cmplen;
+	const char *lead;
+
+	if (len1 < len2) {
+		cmplen = len1;
+		lead = refname2;
+	} else {
+		cmplen = len2;
+		lead = refname1;
+	}
+	return !strncmp(refname1, refname2, cmplen) && lead[cmplen] == '/';
+}
+
 /*
  * Return true iff a reference named refname could be created without
  * conflicting with the name of an existing reference.  If oldrefname
@@ -343,20 +367,15 @@ static int do_for_each_ref_in_arrays(struct ref_array *array1,
 static int is_refname_available(const char *refname, const char *oldrefname,
 				struct ref_array *array)
 {
-	int i, namlen = strlen(refname); /* e.g. 'foo/bar' */
+	int i;
 	for (i = 0; i < array->nr; i++) {
 		struct ref_entry *entry = array->refs[i];
-		/* entry->name could be 'foo' or 'foo/bar/baz' */
-		if (!oldrefname || strcmp(oldrefname, entry->name)) {
-			int len = strlen(entry->name);
-			int cmplen = (namlen < len) ? namlen : len;
-			const char *lead = (namlen < len) ? entry->name : refname;
-			if (!strncmp(refname, entry->name, cmplen) &&
-			    lead[cmplen] == '/') {
-				error("'%s' exists; cannot create '%s'",
-				      entry->name, refname);
-				return 0;
-			}
+		if (oldrefname && !strcmp(oldrefname, entry->name))
+			continue;
+		if (names_conflict(refname, entry->name)) {
+			error("'%s' exists; cannot create '%s'",
+			      entry->name, refname);
+			return 0;
 		}
 	}
 	return 1;
@@ -1333,36 +1352,45 @@ struct ref_lock *lock_any_ref_for_update(const char *refname,
 	return lock_ref_sha1_basic(refname, old_sha1, flags, NULL);
 }
 
+struct repack_without_ref_sb {
+	const char *refname;
+	int fd;
+};
+
+static int repack_without_ref_fn(const char *refname, const unsigned char *sha1,
+				 int flags, void *cb_data)
+{
+	struct repack_without_ref_sb *data = cb_data;
+	char line[PATH_MAX + 100];
+	int len;
+
+	if (!strcmp(data->refname, refname))
+		return 0;
+	len = snprintf(line, sizeof(line), "%s %s\n",
+		       sha1_to_hex(sha1), refname);
+	/* this should not happen but just being defensive */
+	if (len > sizeof(line))
+		die("too long a refname '%s'", refname);
+	write_or_die(data->fd, line, len);
+	return 0;
+}
+
 static struct lock_file packlock;
 
 static int repack_without_ref(const char *refname)
 {
-	struct ref_array *packed;
-	int fd, i;
-
-	packed = get_packed_refs(get_ref_cache(NULL));
+	struct repack_without_ref_sb data;
+	struct ref_array *packed = get_packed_refs(get_ref_cache(NULL));
+	sort_ref_array(packed);
 	if (search_ref_array(packed, refname) == NULL)
 		return 0;
-	fd = hold_lock_file_for_update(&packlock, git_path("packed-refs"), 0);
-	if (fd < 0) {
+	data.refname = refname;
+	data.fd = hold_lock_file_for_update(&packlock, git_path("packed-refs"), 0);
+	if (data.fd < 0) {
 		unable_to_lock_error(git_path("packed-refs"), errno);
 		return error("cannot delete '%s' from packed refs", refname);
 	}
-
-	for (i = 0; i < packed->nr; i++) {
-		char line[PATH_MAX + 100];
-		int len;
-		struct ref_entry *ref = packed->refs[i];
-
-		if (!strcmp(refname, ref->name))
-			continue;
-		len = snprintf(line, sizeof(line), "%s %s\n",
-			       sha1_to_hex(ref->sha1), ref->name);
-		/* this should not happen but just being defensive */
-		if (len > sizeof(line))
-			die("too long a refname '%s'", ref->name);
-		write_or_die(fd, line, len);
-	}
+	do_for_each_ref_in_array(packed, 0, "", repack_without_ref_fn, 0, 0, &data);
 	return commit_lock_file(&packlock);
 }