From: Sven Verdoolaege <skimo@xxxxxxxxxx>
If the function called by for_each_ref modifies a ref in any way,
the cached_refs that for_each_ref was looping over would be
removed, resulting in undefined behavior.
This patch prevents the cached_refs from being removed
while for_each_ref is still iterating over them.
Signed-off-by: Sven Verdoolaege <skimo@xxxxxxxxxx>
---
refs.c | 37 +++++++++++++++++++++++++++++++++----
1 files changed, 33 insertions(+), 4 deletions(-)
diff --git a/refs.c b/refs.c
index 4dc7e8b..e710903 100644
--- a/refs.c
+++ b/refs.c
@@ -153,6 +153,8 @@ static struct ref_list *sort_ref_list(struct ref_list *list)
static struct cached_refs {
char did_loose;
char did_packed;
+ char is_locked;
+ char is_invalidated;
struct ref_list *loose;
struct ref_list *packed;
} cached_refs;
@@ -170,6 +172,11 @@ static void invalidate_cached_refs(void)
{
struct cached_refs *ca = &cached_refs;
+ if (ca->is_locked) {
+ ca->is_invalidated = 1;
+ return;
+ }
+
if (ca->did_loose && ca->loose)
free_ref_list(ca->loose);
if (ca->did_packed && ca->packed)
@@ -178,6 +185,24 @@ static void invalidate_cached_refs(void)
ca->did_loose = ca->did_packed = 0;
}
+static void lock_cached_refs(void)
+{
+ struct cached_refs *ca = &cached_refs;
+
+ ca->is_locked = 1;
+}
+
+static void unlock_cached_refs(void)
+{
+ struct cached_refs *ca = &cached_refs;
+
+ ca->is_locked = 0;
+ if (ca->is_invalidated) {
+ invalidate_cached_refs();
+ ca->is_invalidated = 0;
+ }
+}
+
static void read_packed_refs(FILE *f, struct cached_refs *cached_refs)
{
struct ref_list *list = NULL;
@@ -518,10 +543,12 @@ int peel_ref(const char *ref, unsigned char *sha1)
static int do_for_each_ref(const char *base, each_ref_fn fn, int trim,
void *cb_data)
{
- int retval;
+ int retval = 0;
struct ref_list *packed = get_packed_refs();
struct ref_list *loose = get_loose_refs();
+ lock_cached_refs();
+
while (packed && loose) {
struct ref_list *entry;
int cmp = strcmp(packed->name, loose->name);
@@ -538,15 +565,17 @@ static int do_for_each_ref(const char *base, each_ref_fn fn, int trim,
}
retval = do_one_ref(base, fn, trim, cb_data, entry);
if (retval)
- return retval;
+ goto out;
}
for (packed = packed ? packed : loose; packed; packed = packed->next) {
retval = do_one_ref(base, fn, trim, cb_data, packed);
if (retval)
- return retval;
+ goto out;
}
- return 0;
+ out:
+ unlock_cached_refs();
+ return retval;
}
int head_ref(each_ref_fn fn, void *cb_data)
--
1.5.3.rc0.100.ge60b4
-
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