[PATCH 08/12] builtin/checkout: clear pending objects after diffing

From: "Andrzej Hunt via GitGitGadget" <gitgitgadget@gmail.com>
To: git@vger.kernel.org
Cc: Andrzej Hunt <andrzej@ahunt.org>, Andrzej Hunt <ajrhunt@google.com>
Subject: [PATCH 08/12] builtin/checkout: clear pending objects after diffing
Date: Fri, 09 Apr 2021 18:47:27 +0000	[thread overview]
Message-ID: <cdeb4b7875e3bf66bf2b492841118bab0e8f047e.1617994052.git.gitgitgadget@gmail.com> (raw)
In-Reply-To: <pull.929.git.1617994052.gitgitgadget@gmail.com>

From: Andrzej Hunt <ajrhunt@google.com>

add_pending_object() populates rev.pending, we need to take care of
clearing it once we're done.

This code is run close to the end of a checkout, therefore this leak
seems like it would have very little impact. See also LSAN output
from t0020 below:

Direct leak of 2048 byte(s) in 1 object(s) allocated from:
    #0 0x49ab79 in realloc ../projects/compiler-rt/lib/asan/asan_malloc_linux.cpp:164:3
    #1 0x9acc46 in xrealloc wrapper.c:126:8
    #2 0x83e3a3 in add_object_array_with_path object.c:337:3
    #3 0x8f672a in add_pending_object_with_path revision.c:329:2
    #4 0x8eaeab in add_pending_object_with_mode revision.c:336:2
    #5 0x8eae9d in add_pending_object revision.c:342:2
    #6 0x5154a0 in show_local_changes builtin/checkout.c:602:2
    #7 0x513b00 in merge_working_tree builtin/checkout.c:979:3
    #8 0x512cb3 in switch_branches builtin/checkout.c:1242:9
    #9 0x50f8de in checkout_branch builtin/checkout.c:1646:9
    #10 0x50ba12 in checkout_main builtin/checkout.c:2003:9
    #11 0x5086c0 in cmd_checkout builtin/checkout.c:2055:8
    #12 0x4cd91d in run_builtin git.c:467:11
    #13 0x4cb5f3 in handle_builtin git.c:719:3
    #14 0x4ccf47 in run_argv git.c:808:4
    #15 0x4caf49 in cmd_main git.c:939:19
    #16 0x69e43e in main common-main.c:52:11
    #17 0x7f5dd1d50349 in __libc_start_main (/lib64/libc.so.6+0x24349)

SUMMARY: AddressSanitizer: 2048 byte(s) leaked in 1 allocation(s).
Signed-off-by: Andrzej Hunt <ajrhunt@google.com>
---
 builtin/checkout.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/builtin/checkout.c b/builtin/checkout.c
index 4c696ef4805b..190153c81571 100644
--- a/builtin/checkout.c
+++ b/builtin/checkout.c
@@ -602,6 +602,7 @@ static void show_local_changes(struct object *head,
 	diff_setup_done(&rev.diffopt);
 	add_pending_object(&rev, head, NULL);
 	run_diff_index(&rev, 0);
+	object_array_clear(&rev.pending);
 }
 
 static void describe_detached_head(const char *msg, struct commit *commit)
-- 
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