Re: svn diff produces a patch which does not reapply cleanly

David Glasser wrote:
> On Wed, Jan 7, 2009 at 10:07 AM, Stefan Kueng <tortoisesvn_at_gmail.com> wrote:
>> David Ellingsworth wrote:
>>> On Wed, Jan 7, 2009 at 11:26 AM, Stefan Küng <tortoisesvn_at_gmail.com> wrote:
>>>> Daniel Shahaf wrote:
>>>>> David Ellingsworth wrote on Tue, 6 Jan 2009 at 19:57 -0500:
>>>>>> While using TortoiseSVN 1.5.6 build 14908, I encountered an error
>>>>>> while trying to apply a patch with TortoiseMerge that was previously
>>>>>> created using TortoiseSVN's "Create Patch" feature. While I was unable
>>>>>> to apply the patch with TortoiseMerge, I did succeed while using the
>>>>>> standard patch command, but not without any fuzz.
>>>>>>
>>>>>> The reply to the issue I posted on TortioseSVN"s user mailing list
>>>>>> indicates this is an error in svn's core since the patch generated is
>>>>>> equivalent to "svn diff file > patchfile". I have verified this using
>>>>>> svn client 1.5.1 and 1.5.5.
>>>>>>
>>>>>> Attached are some files I created which are capable of reliably
>>>>>> reproducing the problem. The files are as follows: the original
>>>>>> file(test.txt), the updated file(test_v2.txt), and the associated
>>>>>> patch file generated from svn diff(test.patch).
>>>>>>
>>>>> What *exactly* should we do with these three files to reproduce the error?
>>>>> (If you can package the answer in script (or transcript) form, that's
>>>>> best.) I tried
>>>>>
>>>>> svn add wc1\trunk\test.txt
>>>>> svn commit wc1 -m "add"
>>>>> rm -f wc1\trunk\test.txt
>>>>> cp wc1\trunk\test_v2.txt wc1\trunk\test.txt
>>>>> svn diff wc1 > out
>>>>> vim -Nu NONE -c "%s/\r//" -c "wq ++ff=dos" out
>>>>> svn revert wc1\trunk\test.txt
>>>>> patch -d wc1\trunk < out
>>>>> diff -u wc1\trunk\test*.txt
>>>>>
>>>>> but it didn't cause any error message, and the 'diff -u' at the end also
>>>>> found no differences (the expected result). Results are the same with
>>>>> both 1.5 and trunk.
>>>> Try
>>>>
>>>> svn add wc1\trunk\test.txt
>>>> svn commit wc1 -m "add"
>>>> cp test_v2.txt wc1\trunk\test.txt
>>>> svn diff wc1 > out
>>>> svn revert wc1\trunk\test.txt
>>>> patch -d wc1\trunk < out
>>>>
>>>> Stefan
>>>>
>>> Output is as follows, I don't have a trunk directory so it's been excluded:
>>>
>>> $ svn add wc1\test.txt
>>> A wc1\test.txt
>>>
>>> $ svn commit wc1 -m "add"
>>> Adding wc1\test.txt
>>> Transmitting file data .
>>> Committed revision 1.
>>>
>>> $ cp test_v2.txt wc1\test.txt
>>>
>>> $ svn diff wc1 > out
>>>
>>> $ svn revert wc1\test.txt
>>> Reverted 'wc1\test.txt'
>>>
>>> $ patch -d wc1 < out
>>> patching file 'test.txt'
>>> Hunk #2 succeeded at 7 (offset 2 lines)
>> sure, the patch can be applied, but not cleanly - 'offset 2 lines'.
>> The patch should be applied cleanly, without any offset.
>>
>> I haven't found any clear docs on how a patch file really is defined,
>> but from what I think is wrong:
>>
>> The chunk info line
>> @@ -2,9 +5,9 @@
>> is wrong. AFAIK the first number (-2) is the line number where removing
>> starts, the second one the number of lines to remove (including context
>> lines), the third one (5) the line number where adding starts and the
>> fourth (9) the number of lines to add (also including context lines).
>>
>> Now, in 1.4.x, the diff would have the start line numbers adjusted. The
>> first chunk is always correct, but now (>= 1.5.x) the line numbers are
>> always in reference to the original file. Before those lines were
>> adjusted: if a chunk before added lines or removed lines, the 'start'
>> lines of the following chunks would take that into account.
>>
>> Does anyone know if (and where) the patch file format is documented?
>> Because I may be completely wrong here - I've implemented the patch
>> functionality in TortoiseMerge completely by reverse engineering the
>> format...
>
> I get the same patch with 1.4.x and ~trunk (with that line), FWIW.
> You get something different with 1.4.x?

hmm - no. I also get the same patch with 1.4.x and even 1.3.x.

Problem still is: the original 'patch' tool can't apply that patch
cleanly without doing 'fuzzy' work. Which means the patch is not correct?

If there was a documentation on how a patch has to be created and how
those chunk infos are supposed to work, it would be easier...

Stefan

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