Subject: Re: [PATCH] git apply: binary files differ can be applied with -pN (N>1).

From: Jiang Xin <[email-masked]>
Date: Wed, 24 Nov 2010 14:53:39 +0800

How to reproduce the bug:

1. Generate a patch file against two directory with binary diff.
================================================================

$ mkdir hello-1.0 hello-2.0

$ dd if=/bin/ls of=hello-1.0/binary.dat count=1 bs=32
1+0 records in
1+0 records out
32 bytes (32 B) copied, 0.00121276 s, 26.4 kB/s

$ dd if=/bin/ls of=hello-2.0/binary.dat count=1 bs=64
1+0 records in
1+0 records out
64 bytes (64 B) copied, 0.00030288 s, 211 kB/s

$ git diff --no-index --binary hello-1.0 hello-2.0 > patch.txt

2. The patch file has patch level 2
===================================

$ cat patch.txt 
diff --git a/hello-1.0/binary.dat b/hello-2.0/binary.dat
index dc2e37f81e0fa88308bec48cd5195b6542e61a20..bf948689934caf2d874ff8168cb716fbc2a127c3 100644
GIT binary patch
delta 37
hcmY#zn4qBGzyJX+<}pH93=9qo77QFfQiegA0RUZd1MdI;

delta 4
LcmZ=zn4kav0;B;E

3. Apply the patch failed
=========================

$ cd hello-1.0

$ git apply --check -p2 ../patch.txt
fatal: git diff header lacks filename information when removing 2 leading pathname components (line 3)

于 2010年11月24日 13:20, Jiang Xin 写道:
> When patch file generated against two non-git directories using
> 'git diff --binary --no-index' without '--no-prefix', the patch
> file has patch level greater then 1, and should be applied with
> '-p2' option. But it does not work if there are binary differ
> in the patch file, it is because in one case the patch level is
> not properly handled.
> 
> Signed-off-by: Jiang Xin <[email-masked]>
> ---
>  builtin/apply.c |    3 ++-
>  1 files changed, 2 insertions(+), 1 deletions(-)
> 
> diff --git a/builtin/apply.c b/builtin/apply.c
> index 23c18c5..d603e37 100644
> --- a/builtin/apply.c
> +++ b/builtin/apply.c
> @@ -1126,6 +1126,7 @@ static char *git_header_name(char *line, int llen)
>  	 * form.
>  	 */
>  	for (len = 0 ; ; len++) {
> +		int nslash = p_value;
>  		switch (name[len]) {
>  		default:
>  			continue;
> @@ -1137,7 +1138,7 @@ static char *git_header_name(char *line, int llen)
>  				char c = *second++;
>  				if (c == '\n')
>  					return NULL;
> -				if (c == '/')
> +				if (c == '/' && --nslash <= 0)
>  					break;
>  			}
>  			if (second[len] == '\n' && !memcmp(name, second, len)) {

-- 
蒋鑫

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