[PATCH v2 06/12] dir: free allocations on parse-error paths in `read_one_dir()`

["Johannes Schindelin via GitGitGadget" <gitgitgadget@gmail.com>]

From: Johannes Schindelin <johannes.schindelin@gmx.de>

Two of `read_one_dir()`'s parse-error early returns leak ud.untracked
and ud.dirs. Plug them.

The other early returns in the same function are fine: they occur after
the `xmalloc()`+`memcpy()` that copies ud into `*untracked_`, at which
point ownership is transferred to the caller.
`read_untracked_extension()` then releases everything via
`free_untracked_cache()` on failure.

Pointed out by Coverity.

Assisted-by: Claude Opus 4.6
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
---
 dir.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/dir.c b/dir.c
index 32430090dc..23335b9f7a 100644
--- a/dir.c
+++ b/dir.c
@@ -3792,13 +3792,18 @@ static int read_one_dir(struct untracked_cache_dir **untracked_,
 		ALLOC_ARRAY(ud.untracked, ud.untracked_nr);
 
 	ud.dirs_alloc = ud.dirs_nr = decode_varint(&data);
-	if (data > end)
+	if (data > end) {
+		free(ud.untracked);
 		return -1;
+	}
 	ALLOC_ARRAY(ud.dirs, ud.dirs_nr);
 
 	eos = memchr(data, '\0', end - data);
-	if (!eos || eos == end)
+	if (!eos || eos == end) {
+		free(ud.untracked);
+		free(ud.dirs);
 		return -1;
+	}
 
 	*untracked_ = untracked = xmalloc(st_add3(sizeof(*untracked), eos - data, 1));
 	memcpy(untracked, &ud, sizeof(ud));
-- 
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