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

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...

Stefan

-- 
       ___
  oo  // \\      "De Chelonian Mobile"
 (_,\/ \_/ \     TortoiseSVN
   \ \_/_\_/>    The coolest Interface to (Sub)Version Control
   /_/   \_\     http://tortoisesvn.net
------------------------------------------------------
http://subversion.tigris.org/ds/viewMessage.do?dsForumId=462&dsMessageId=1010205