[PATCH] apply: Recognize epoch timestamps with : in the timezone

[PATCH] apply: Recognize epoch timestamps with : in the timezone

[Anders Kaseorg]

Some patches have a timezone formatted like ‘-08:00’ instead of
‘-0800’ (e.g. http://lwn.net/Articles/131729/), so git apply would
fail to recognize the epoch timestamp of deleted files and would
create empty files instead.  Teach it to support both formats, and add
a test case.

Signed-off-by: Anders Kaseorg <andersk@mit.edu>
---
 builtin/apply.c          |    6 ++++--
 t/t4132-apply-removal.sh |    2 ++
 2 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/builtin/apply.c b/builtin/apply.c
index 23c18c5..0fa9a8d 100644
--- a/builtin/apply.c
+++ b/builtin/apply.c
@@ -733,7 +733,7 @@ static int has_epoch_timestamp(const char *nameline)
 		" "
 		"[0-2][0-9]:[0-5][0-9]:00(\\.0+)?"
 		" "
-		"([-+][0-2][0-9][0-5][0-9])\n";
+		"([-+][0-2][0-9]):?([0-5][0-9])\n";
 	const char *timestamp = NULL, *cp;
 	static regex_t *stamp;
 	regmatch_t m[10];
@@ -765,7 +765,9 @@ static int has_epoch_timestamp(const char *nameline)
 	}
 
 	zoneoffset = strtol(timestamp + m[3].rm_so + 1, NULL, 10);
-	zoneoffset = (zoneoffset / 100) * 60 + (zoneoffset % 100);
+	if (m[4].rm_so == m[3].rm_so + 3)
+		zoneoffset /= 100;
+	zoneoffset = zoneoffset * 60 + strtol(timestamp + m[4].rm_so, NULL, 10);
 	if (timestamp[m[3].rm_so] == '-')
 		zoneoffset = -zoneoffset;
 
diff --git a/t/t4132-apply-removal.sh b/t/t4132-apply-removal.sh
index bb1ffe3..a2bc1cd 100755
--- a/t/t4132-apply-removal.sh
+++ b/t/t4132-apply-removal.sh
@@ -30,6 +30,7 @@ test_expect_success setup '
 	epocWest="1969-12-31 16:00:00.000000000 -0800" &&
 	 epocGMT="1970-01-01 00:00:00.000000000 +0000" &&
 	epocEast="1970-01-01 09:00:00.000000000 +0900" &&
+	epocWest2="1969-12-31 16:00:00 -08:00" &&
 
 	sed -e "s/TS0/$epocWest/" -e "s/TS1/$timeWest/" <c >createWest.patch &&
 	sed -e "s/TS0/$epocEast/" -e "s/TS1/$timeEast/" <c >createEast.patch &&
@@ -46,6 +47,7 @@ test_expect_success setup '
 	sed -e "s/TS0/$timeWest/" -e "s/TS1/$epocWest/" <d >removeWest.patch &&
 	sed -e "s/TS0/$timeEast/" -e "s/TS1/$epocEast/" <d >removeEast.patch &&
 	sed -e "s/TS0/$timeGMT/" -e "s/TS1/$epocGMT/" <d >removeGMT.patch &&
+	sed -e "s/TS0/$timeWest/" -e "s/TS1/$epocWest2/" <d >removeWest2.patch &&
 
 	echo something >something &&
 	>empty
-- 
1.7.3

Re: [PATCH] apply: Recognize epoch timestamps with : in the timezone

[Jonathan Nieder]

Hi Anders,

Anders Kaseorg wrote:
> Some patches have a timezone formatted like '-08:00' instead of
> '-0800' (e.g. http://lwn.net/Articles/131729/)

Odd.  Any idea what tool generates these patches?

> --- a/builtin/apply.c
> +++ b/builtin/apply.c
[...]
> @@ -765,7 +765,9 @@ static int has_epoch_timestamp(const char *nameline)
>  	}
>  
>  	zoneoffset = strtol(timestamp + m[3].rm_so + 1, NULL, 10);
> -	zoneoffset = (zoneoffset / 100) * 60 + (zoneoffset % 100);
> +	if (m[4].rm_so == m[3].rm_so + 3)
> +		zoneoffset /= 100;
> +	zoneoffset = zoneoffset * 60 + strtol(timestamp + m[4].rm_so, NULL, 10);

Might be clearer to write

	if (timestamp[m[3].rm_so + 3] != ':')

With or without that change,
Reviewed-by: Jonathan Nieder <jrnieder@gmail.com>

Maybe something like this on top?

-- 8< --
Subject: apply: handle patches with funny filename and colon in timezone

Some patches have a timezone formatted like '-08:00' instead of
'-0800' in their ---/+++ lines (e.g. http://lwn.net/Articles/131729/).
Take this into account when searching for the start of the timezone
(which is the end of the filename).

This does not actually affect the outcome of patching unless (1) a
file being patched has a non-' ' whitespace character (e.g., tab) in
its filename, or (2) the patch is whitespace-damaged, so the tab
between filename and timestamp has been replaced with spaces.

Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
---
 builtin/apply.c                  |   24 ++++++++++++++++++++++--
 t/t4135-apply-weird-filenames.sh |   16 ++++++++++++++++
 t/t4135/damaged-tz.diff          |    5 +++++
 t/t4135/funny-tz.diff            |    5 +++++
 4 files changed, 48 insertions(+), 2 deletions(-)
 create mode 100644 t/t4135/damaged-tz.diff
 create mode 100644 t/t4135/funny-tz.diff

diff --git a/builtin/apply.c b/builtin/apply.c
index 0fa9a8d..7d91d8f 100644
--- a/builtin/apply.c
+++ b/builtin/apply.c
@@ -449,7 +449,7 @@ static char *find_name_gnu(const char *line, char *def, int p_value)
 	return squash_slash(strbuf_detach(&name, NULL));
 }
 
-static size_t tz_len(const char *line, size_t len)
+static size_t sane_tz_len(const char *line, size_t len)
 {
 	const char *tz, *p;
 
@@ -467,6 +467,24 @@ static size_t tz_len(const char *line, size_t len)
 	return line + len - tz;
 }
 
+static size_t tz_with_colon_len(const char *line, size_t len)
+{
+	const char *tz, *p;
+
+	if (len < strlen(" +08:00") || line[len - strlen(":00")] != ':')
+		return 0;
+	tz = line + len - strlen(" +08:00");
+
+	if (tz[0] != ' ' || (tz[1] != '+' && tz[1] != '-'))
+		return 0;
+	p = tz + 2;
+	if (!isdigit(*p++) || !isdigit(*p++) || *p++ != ':' ||
+	    !isdigit(*p++) || !isdigit(*p++))
+		return 0;
+
+	return line + len - tz;
+}
+
 static size_t date_len(const char *line, size_t len)
 {
 	const char *date, *p;
@@ -561,7 +579,9 @@ static size_t diff_timestamp_len(const char *line, size_t len)
 	if (!isdigit(end[-1]))
 		return 0;
 
-	n = tz_len(line, end - line);
+	n = sane_tz_len(line, end - line);
+	if (!n)
+		n = tz_with_colon_len(line, end - line);
 	end -= n;
 
 	n = short_time_len(line, end - line);
diff --git a/t/t4135-apply-weird-filenames.sh b/t/t4135-apply-weird-filenames.sh
index 1e5aad5..bf5dc57 100755
--- a/t/t4135-apply-weird-filenames.sh
+++ b/t/t4135-apply-weird-filenames.sh
@@ -72,4 +72,20 @@ test_expect_success 'whitespace-damaged traditional patch' '
 	test_cmp expected postimage.txt
 '
 
+test_expect_success 'traditional patch with colon in timezone' '
+	echo postimage >expected &&
+	reset_preimage &&
+	rm -f "post image.txt" &&
+	git apply "$vector/funny-tz.diff" &&
+	test_cmp expected "post image.txt"
+'
+
+test_expect_success 'traditional, whitespace-damaged, colon in timezone' '
+	echo postimage >expected &&
+	reset_preimage &&
+	rm -f "post image.txt" &&
+	git apply "$vector/damaged-tz.diff" &&
+	test_cmp expected "post image.txt"
+'
+
 test_done
diff --git a/t/t4135/damaged-tz.diff b/t/t4135/damaged-tz.diff
new file mode 100644
index 0000000..07aaf08
--- /dev/null
+++ b/t/t4135/damaged-tz.diff
@@ -0,0 +1,5 @@
+diff -urN -X /usr/people/jes/exclude-linux linux-2.6.12-rc2-mm3-vanilla/post image.txt linux-2.6.12-rc2-mm3/post image.txt
+--- linux-2.6.12-rc2-mm3-vanilla/post image.txt 1969-12-31 16:00:00 -08:00
++++ linux-2.6.12-rc2-mm3/post image.txt 2005-04-12 02:14:06 -07:00
+@@ -0,0 +1 @@
++postimage
diff --git a/t/t4135/funny-tz.diff b/t/t4135/funny-tz.diff
new file mode 100644
index 0000000..998e3a8
--- /dev/null
+++ b/t/t4135/funny-tz.diff
@@ -0,0 +1,5 @@
+diff -urN -X /usr/people/jes/exclude-linux linux-2.6.12-rc2-mm3-vanilla/post image.txt linux-2.6.12-rc2-mm3/post image.txt
+--- linux-2.6.12-rc2-mm3-vanilla/post image.txt	1969-12-31 16:00:00 -08:00
++++ linux-2.6.12-rc2-mm3/post image.txt	2005-04-12 02:14:06 -07:00
+@@ -0,0 +1 @@
++postimage
-- 
1.6.5

Re: [PATCH] apply: Recognize epoch timestamps with : in the timezone

[Jonathan Nieder]

Jonathan Nieder wrote:

> Some patches have a timezone formatted like '-08:00' instead of
> '-0800' in their ---/+++ lines (e.g. http://lwn.net/Articles/131729/).
> Take this into account when searching for the start of the timezone

s/timezone/timestamp/

> (which is the end of the filename).

Sorry for the noise.

Re: [PATCH] apply: Recognize epoch timestamps with : in the timezone

[Junio C Hamano]

Jonathan Nieder <jrnieder@gmail.com> writes:

> Hi Anders,
>
> Anders Kaseorg wrote:
>> Some patches have a timezone formatted like '-08:00' instead of
>> '-0800' (e.g. http://lwn.net/Articles/131729/)
>
> Odd.  Any idea what tool generates these patches?
>
>> --- a/builtin/apply.c
>> +++ b/builtin/apply.c
> [...]
>> @@ -765,7 +765,9 @@ static int has_epoch_timestamp(const char *nameline)
>>  	}
>>  
>>  	zoneoffset = strtol(timestamp + m[3].rm_so + 1, NULL, 10);
>> -	zoneoffset = (zoneoffset / 100) * 60 + (zoneoffset % 100);
>> +	if (m[4].rm_so == m[3].rm_so + 3)
>> +		zoneoffset /= 100;
>> +	zoneoffset = zoneoffset * 60 + strtol(timestamp + m[4].rm_so, NULL, 10);
>
> Might be clearer to write
>
> 	if (timestamp[m[3].rm_so + 3] != ':')

Neither the patch nor your suggestion makes much sense to me.  With the
patch, the regexp is now

    ^(1969-12-31|1970-01-01) <time>(\.0+)? ([-+][0-2][0-9]):?([0-5][0-9])

so $3 is always 3 letters long (i.e. hour with sign), no?  IOW, zoneoffset
is never divided by 100 by the original patch.

What am I missing?

Re: [PATCH] apply: Recognize epoch timestamps with : in the timezone

[Junio C Hamano]

Junio C Hamano <gitster@pobox.com> writes:

> Neither the patch nor your suggestion makes much sense to me.  With the
> patch, the regexp is now
>
>     ^(1969-12-31|1970-01-01) <time>(\.0+)? ([-+][0-2][0-9]):?([0-5][0-9])
>
> so $3 is always 3 letters long (i.e. hour with sign), no?  IOW, zoneoffset
> is never divided by 100 by the original patch.
>
> What am I missing?

Well, I was missing that without ':' strtol() goes through to parse $3$4
as a single integer, and the division was done to discard the minute part
and parse it again.

Calling strtol() twice only because some unusual input may have ':' there
feels ugly, but now I understand why the patch is written that way, at
least.

Re: [PATCH] apply: Recognize epoch timestamps with : in the timezone

[Jonathan Nieder]

Junio C Hamano wrote:
> Junio C Hamano <gitster@pobox.com> writes:

>> Neither the patch nor your suggestion makes much sense to me.  With the
>> patch, the regexp is now
>>
>>     ^(1969-12-31|1970-01-01) <time>(\.0+)? ([-+][0-2][0-9]):?([0-5][0-9])
[...]
> Well, I was missing that without ':' strtol() goes through to parse $3$4
> as a single integer

So maybe something like the following would make this easier to follow.

diff --git a/builtin/apply.c b/builtin/apply.c
index 0fa9a8d..000d3e5 100644
--- a/builtin/apply.c
+++ b/builtin/apply.c
@@ -733,8 +733,8 @@ static int has_epoch_timestamp(const char *nameline)
 		" "
 		"[0-2][0-9]:[0-5][0-9]:00(\\.0+)?"
 		" "
-		"([-+][0-2][0-9]):?([0-5][0-9])\n";
+		"([-+][0-2][0-9]:?[0-5][0-9])\n";
-	const char *timestamp = NULL, *cp;
+	const char *timestamp = NULL, *cp, *colon;
 	static regex_t *stamp;
 	regmatch_t m[10];
 	int zoneoffset;
@@ -764,10 +764,11 @@ static int has_epoch_timestamp(const char *nameline)
 		return 0;
 	}
 
-	zoneoffset = strtol(timestamp + m[3].rm_so + 1, NULL, 10);
+	zoneoffset = strtol(timestamp + m[3].rm_so + 1, (char **) &colon, 10);
-	if (m[4].rm_so == m[3].rm_so + 3)
-		zoneoffset /= 100;
-	zoneoffset = zoneoffset * 60 + strtol(timestamp + m[4].rm_so, NULL, 10);
+	if (*colon == ':')
+		zoneoffset = zoneoffset * 60 + strtol(colon + 1, NULL, 10);
+	else
+		zoneoffset = (zoneoffset / 100) * 60 + (zoneoffset % 100);
 	if (timestamp[m[3].rm_so] == '-')
 		zoneoffset = -zoneoffset;
 

Re: [PATCH] apply: Recognize epoch timestamps with : in the timezone

[Junio C Hamano]

Jonathan Nieder <jrnieder@gmail.com> writes:

> Junio C Hamano wrote:
>> Junio C Hamano <gitster@pobox.com> writes:
>
>>> Neither the patch nor your suggestion makes much sense to me.  With the
>>> patch, the regexp is now
>>>
>>>     ^(1969-12-31|1970-01-01) <time>(\.0+)? ([-+][0-2][0-9]):?([0-5][0-9])
> [...]
>> Well, I was missing that without ':' strtol() goes through to parse $3$4
>> as a single integer
>
> So maybe something like the following would make this easier to follow.

Yeah, this feels much more natural.

> diff --git a/builtin/apply.c b/builtin/apply.c
> index 0fa9a8d..000d3e5 100644
> --- a/builtin/apply.c
> +++ b/builtin/apply.c
> @@ -733,8 +733,8 @@ static int has_epoch_timestamp(const char *nameline)
>  		" "
>  		"[0-2][0-9]:[0-5][0-9]:00(\\.0+)?"
>  		" "
> -		"([-+][0-2][0-9]):?([0-5][0-9])\n";
> +		"([-+][0-2][0-9]:?[0-5][0-9])\n";
> -	const char *timestamp = NULL, *cp;
> +	const char *timestamp = NULL, *cp, *colon;
>  	static regex_t *stamp;
>  	regmatch_t m[10];
>  	int zoneoffset;
> @@ -764,10 +764,11 @@ static int has_epoch_timestamp(const char *nameline)
>  		return 0;
>  	}
>  
> -	zoneoffset = strtol(timestamp + m[3].rm_so + 1, NULL, 10);
> +	zoneoffset = strtol(timestamp + m[3].rm_so + 1, (char **) &colon, 10);
> -	if (m[4].rm_so == m[3].rm_so + 3)
> -		zoneoffset /= 100;
> -	zoneoffset = zoneoffset * 60 + strtol(timestamp + m[4].rm_so, NULL, 10);
> +	if (*colon == ':')
> +		zoneoffset = zoneoffset * 60 + strtol(colon + 1, NULL, 10);
> +	else
> +		zoneoffset = (zoneoffset / 100) * 60 + (zoneoffset % 100);
>  	if (timestamp[m[3].rm_so] == '-')
>  		zoneoffset = -zoneoffset;
>