Wireshark · Ethereal-dev: Re: [Ethereal-dev] What's the recommended way to use the patch tool?

[Ulf Lamping <ulf.lamping@xxxxxx>]

Guy Harris wrote:

> Ulf Lamping wrote:
>
> > Given the file "new.diff" containing a unified diff, what is the 
> > right way to call the patch tool?
>
>
> That depends on what the pathnames in "new.diff" look like. 
There are "usually" two pathnames in the patch, what does the patch tool 
do, if they have different "lengths", e.g.:

diff -ur ../ethereal-0.10.6/epan/dissectors/packet-dcerpc.c 
./epan/dissectors/packet-dcerpc.c
--- ../ethereal-0.10.6/epan/dissectors/packet-dcerpc.c    2004-08-12 
15:42:26.000000000 -0700
+++ ./epan/dissectors/packet-dcerpc.c    2004-08-19 18:48:32.000000000 -0700

Will the patch tool use the shorter path (in this case the second one)?

I think I would have to call "patch -p0 <new.diff" in the ethereal 
source root dir to patch my sources, am I correct here?

> > Is there a difference when the diff file contains one file "diff -u" 
> > or more files "diff -ur"?
>
>
> There isn't a difference in the arguments to "patch".
>
> (However, there is a difference in the number of times you have to run 
> "patch" - and the number of times you have to save a patch file from 
> mail - so I, at least, prefer it when people send a single patch file 
> with patches for all the files to be changed.)
missunderstanding: I meant in both cases one diff file containing one 
file with diffs in one case and multiple files with diffs in the other 
case. From the answer you gave I would guess that there is no difference 
on how to call the patch tool.

> > At which position in the filesystem has the patch tool to be called?
>
>
> If the pathnames are relative to the top-level source directory, or to 
> a directory above that directory, you'd run it in the top-level source 
> directory.
>
> If they're relative to a *subdirectory* - for example, if somebody did 
> a patch to "packet-ip.c" and ran "diff" or "svn diff" in the 
> "epan/dissectors" directory - you'd run it in that subdirectory.  (I 
> would really prefer that people *NOT* submit patches like that - 
> especially if they're only patching files that exist in multiple 
> directories, such as "Makefile.am".)
Well, I think, the main reason why people do it that way is just that we 
don't have any good documentation how to make a "correct" diff file, but 
I'm currently working exactly on this :-)

I've took parts of your mail formatted it into docbook and put it into 
the developer's guide, I hope your fine with it (like the lot of 
information before, coming from you :-)))

Regards, ULFL