pack-objects (mingw): demonstrate a segmentation fault with large deltas

There is a problem in the way 9ac3f0e5b3e4 (pack-objects: fix performance issues on packing large deltas, 2018-07-22) initializes that mutex in the `packing_data` struct. The problem manifests in a segmentation fault on Windows, when a mutex (AKA critical section) is accessed without being initialized. (With pthreads, you apparently do not really have to initialize them?) This was reported in https://github.com/git-for-windows/git/issues/1839. Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>

Johannes Schindelin committed Oct 16, 2018 at 14:02 UTC 9308f45a9f1e3e107ba53a91d0f0c59342cb32bd
1 file changed +32
t/t5321-pack-large-objects.sh new
+32
@@ -0,0 +1,32 @@
1 +#!/bin/sh
2 +#
3 +# Copyright (c) 2018 Johannes Schindelin
4 +#
5 +
6 +test_description='git pack-object with "large" deltas
7 +
8 +'
9 +. ./test-lib.sh
10 +. "$TEST_DIRECTORY"/lib-pack.sh
11 +
12 +# Two similar-ish objects that we have computed deltas between.
13 +A=01d7713666f4de822776c7622c10f1b07de280dc
14 +B=e68fe8129b546b101aee9510c5328e7f21ca1d18
15 +
16 +test_expect_success 'setup' '
17 + clear_packs &&
18 + {
19 + pack_header 2 &&
20 + pack_obj $A $B &&
21 + pack_obj $B
22 + } >ab.pack &&
23 + pack_trailer ab.pack &&
24 + git index-pack --stdin <ab.pack
25 +'
26 +
27 +test_expect_failure 'repack large deltas' '
28 + printf "%s\\n" $A $B |
29 + GIT_TEST_OE_DELTA_SIZE=2 git pack-objects tmp-pack
30 +'
31 +
32 +test_done