Re: [PATCH] maintenance: fix two memory leaks

["lilinchao@oschina.cn" <lilinchao@oschina.cn>]

Hi,

>Fixes two memory leaks when running `git maintenance start` or `git
>maintenance stop` in `update_background_schedule`:
>
>$ valgrind --leak-check=full ~/git/bin/git maintenance start
>==76584== Memcheck, a memory error detector
>==76584== Copyright (C) 2002-2017, and GNU GPL'd, by Julian Seward et al.
>==76584== Using Valgrind-3.16.1 and LibVEX; rerun with -h for copyright info
>==76584== Command: /home/lenaic/git/bin/git maintenance start
>==76584==
>==76584==
>==76584== HEAP SUMMARY:
>==76584==     in use at exit: 34,880 bytes in 252 blocks
>==76584==   total heap usage: 820 allocs, 568 frees, 146,414 bytes allocated
>==76584==
>==76584== 65 bytes in 1 blocks are definitely lost in loss record 17 of 39
>==76584==    at 0x483E6AF: malloc (vg_replace_malloc.c:306)
>==76584==    by 0x3DC39C: xrealloc (wrapper.c:126)
>==76584==    by 0x3992CC: strbuf_grow (strbuf.c:98)
>==76584==    by 0x39A473: strbuf_vaddf (strbuf.c:392)
>==76584==    by 0x39BC54: xstrvfmt (strbuf.c:979)
>==76584==    by 0x39BD2C: xstrfmt (strbuf.c:989)
>==76584==    by 0x18451B: update_background_schedule (gc.c:1977)
>==76584==    by 0x1846F6: maintenance_start (gc.c:2011)
>==76584==    by 0x1847B4: cmd_maintenance (gc.c:2030)
>==76584==    by 0x127A2E: run_builtin (git.c:453)
>==76584==    by 0x127E81: handle_builtin (git.c:704)
>==76584==    by 0x128142: run_argv (git.c:771)
>==76584==
>==76584== 240 bytes in 1 blocks are definitely lost in loss record 29 of 39
>==76584==    at 0x4840D7B: realloc (vg_replace_malloc.c:834)
>==76584==    by 0x491CE5D: getdelim (in /usr/lib/libc-2.33.so)
>==76584==    by 0x39ADD7: strbuf_getwholeline (strbuf.c:635)
>==76584==    by 0x39AF31: strbuf_getdelim (strbuf.c:706)
>==76584==    by 0x39B064: strbuf_getline_lf (strbuf.c:727)
>==76584==    by 0x184273: crontab_update_schedule (gc.c:1919)
>==76584==    by 0x184678: update_background_schedule (gc.c:1997)
>==76584==    by 0x1846F6: maintenance_start (gc.c:2011)
>==76584==    by 0x1847B4: cmd_maintenance (gc.c:2030)
>==76584==    by 0x127A2E: run_builtin (git.c:453)
>==76584==    by 0x127E81: handle_builtin (git.c:704)
>==76584==    by 0x128142: run_argv (git.c:771)
>==76584==
>==76584== LEAK SUMMARY:
>==76584==    definitely lost: 305 bytes in 2 blocks
>==76584==    indirectly lost: 0 bytes in 0 blocks
>==76584==      possibly lost: 0 bytes in 0 blocks
>==76584==    still reachable: 34,575 bytes in 250 blocks
>==76584==         suppressed: 0 bytes in 0 blocks
>==76584== Reachable blocks (those to which a pointer was found) are not shown.
>==76584== To see them, rerun with: --leak-check=full --show-leak-kinds=all
>==76584==
>==76584== For lists of detected and suppressed errors, rerun with: -s
>==76584== ERROR SUMMARY: 2 errors from 2 contexts (suppressed: 0 from 0)
>
>Signed-off-by: Lénaïc Huard <lenaic@lhuard.fr>
>---
> builtin/gc.c | 2 ++
> 1 file changed, 2 insertions(+)
>
>diff --git a/builtin/gc.c b/builtin/gc.c
>index ef7226d7bc..2574068ae2 100644
>--- a/builtin/gc.c
>+++ b/builtin/gc.c
>@@ -1947,6 +1947,7 @@ static int crontab_update_schedule(int run_maintenance, int fd, const char *cmd)
> fprintf(cron_in, "\n%s\n", END_LINE);
> }
>
>+	strbuf_release(&line); 
> fflush(cron_in);
> fclose(cron_in);
> close(crontab_edit.in);
>@@ -1999,6 +2000,7 @@ static int update_background_schedule(int enable)
> die("unknown background scheduler: %s", scheduler);
>
> rollback_lock_file(&lk);
>+	free(lock_path); 
Based on your change, I think when "hold_lock_file_for_update()<0", we should also free local_path

> free(testing);
> return result;
> }
>--
>2.31.1
>
> 

Thanks