In `reftable_stack_init_addition()` we call `stack_uptodate()` after
having created the lockfile to check whether the stack was modified
concurrently, which is indicated by a positive return code from the
latter function. If so, we return a `REFTABLE_LOCK_ERROR` to the caller
and abort the addition.
The error handling has an off-by-one though because we check whether the
error code is `> 1` instead of `> 0`. Thus, instead of returning the
locking error, we would return a positive value. One of the callers of
`reftable_stack_init_addition()` works around this bug by repeating the
error code check without the off-by-one. But other callers are subtly
broken by this bug.
Fix this by checking for `err > 0` instead.
Signed-off-by: Patrick Steinhardt <ps@xxxxxx>
---
reftable/stack.c | 7 +------
1 file changed, 1 insertion(+), 6 deletions(-)
diff --git a/reftable/stack.c b/reftable/stack.c
index 1ecf1b9751..92d9a7facb 100644
--- a/reftable/stack.c
+++ b/reftable/stack.c
@@ -590,8 +590,7 @@ static int reftable_stack_init_addition(struct reftable_addition *add,
err = stack_uptodate(st);
if (err < 0)
goto done;
-
- if (err > 1) {
+ if (err > 0) {
err = REFTABLE_LOCK_ERROR;
goto done;
}
@@ -713,10 +712,6 @@ static int stack_try_add(struct reftable_stack *st,
int err = reftable_stack_init_addition(&add, st);
if (err < 0)
goto done;
- if (err > 0) {
- err = REFTABLE_LOCK_ERROR;
- goto done;
- }
err = reftable_addition_add(&add, write_table, arg);
if (err < 0)
--
2.44.0
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