Re: any good diff merging utility?

[Ivan Vadovic]

>  > I like to build kernels with a bunch of patches on top to test
>  > new stuff. The problem is that it takes a lot of effort to fix
>  > all the failed hunks during patching that really wouldn't have
>  > to be failed if only patch was a little more inteligent and
>  > could merge several patches into one ( if possible) or if could
>  > take into account already applied patches.
> 
> The basic problem here is that the "failed hunks" are usually there
> because of conflicts between the two patches in question, and as a
> result, they are not as easy to merge automagically as one might at
> first assume.

Very often the case is that they indeed can be merged automagically.
For example two patches inserting few lines right after the #include
lines.

patch1:
@@ 10,1 10,2 @@
 #include <foo.h>
+#include <1.h>

patch2:
@@ 10,1 10,2 @@
 #include <foo.h>
+#include <2.h>

The patch will fail to patch :-). But there is no real conflict between
the patches.
 
>  > Well, are there any utilities to merge diffs? I couldn't find
>  > any on freshmeat. So what are you using to stack many patches
>  > onto the kernel tree? Just manualy modify the diff? I'll try to
>  > write something more automatic if nothing comes up.
> 
> I once came across a utility called "diff3" that was designed to take
> a patch for one version of a package and create an equivalent patch
> for another version of the same package, but I haven't been able to
> find it again since my hard drive crashed.

diff3 comes from gnu diffutils
<ftp://ftp.gnu.org/gnu/diffutils/diffutils-2.7.tar.gz>. But all it does
is comparing three FILES for differencies.

Ivan Vadovic