How to sync patches?

[digerati1338]

Just wondering if anyone could give me or point me to a quick lesson on syncing patches.  I have some experience with code, but don't know exactly what needs to be done to sync a patch.  

Thanks for the help.

[cpchan]

Just wondering if anyone could give me or point me to a quick lesson on syncing patches.  I have some experience with code, but don't know exactly what needs to be done to sync a patch.

1. Find all the reject files (they have the .rej extension).

2. Look through them and see what is being rejected and at what location.

3. Modified the source code in the corresponding files.

4. Make a unified diff against the pristine source.

Depending on how much the source have changed, you might need to do some coding or a complete rewrite of the patch.

Charles

[tdtooke]

Basically what he said, you also want to use -r as well as -u.  I use cygwin and this is how I do it exactly:
diff -u -r name_original_source name_modified_source > name_of_patch.patch
Of course if your patch doesn't have any dependencies you could just do a diff against svn, just make sure there haven't been any new commits before you try it.  I don't recommend that though since there is always a chance somebody just upped a change.

[digerati1338]

@cpchan:
1. Ok, I got that.
2. How exactly do I know what is being rejected, and how do i trace and fix the problem?
3. OK
4. Check.

[cpchan]

How exactly do I know what is being rejected,

It is very obvious in the reject files.

and how do i trace and fix the problem?

read and search through the code in the original files.

Charles

[digerati1338]

OK so just to make sure I know what I'm doing:

1. I do a dry-run on a patch, and I see that it is out of sync.  No reject files are created in a dry run, so I have to apply the patch, then reverse-apply it so I keep my clean source?

2.  Check reject file, make necessary changes.

3.  Make a new unified diff.  I assume I need to use unpatched source when I do this?

[cpchan]

so I have to apply the patch, then reverse-apply it so I keep my clean source?

No, you should work with 2 trees- one is the clean pristine (unpatched) source and one is a working copy (for example "rockbox-new").

Check reject file, make necessary changes.

You don't revert the patch. You have to see what is being rejected and modify the source code in your working copy.

Make a new unified diff.  I assume I need to use unpatched source when I do this?

Yes, you make it against the upatched source.

Charles
 

[bascule]

No, you should work with 2 trees- one is the clean pristine (unpatched) source and one is a working copy (for example "rockbox-new")...

...Yes, you make it against the upatched source...

I don't think this is necessary. There is always a (hidden) clean tree available, as this is what SVN automatically does a diff against.

If you need it, you can always do make clean and this will use the clean tree.

[cpchan]

I don't think this is necessary. There is always a (hidden) clean tree available, as this is what SVN automatically does a diff against.

Yes, you are correct. I should really start  learning and using Subversion. I am still doing things the old fashioned way.

Charles

[bascule]

OK so just to make sure I know what I'm doing:

1. I do a dry-run on a patch, and I see that it is out of sync.  No reject files are created in a dry run, so I have to apply the patch, then reverse-apply it so I keep my clean source?

2.  Check reject file, make necessary changes.

3.  Make a new unified diff.  I assume I need to use unpatched source when I do this?

You are correct, except for the reverse-apply.

You apply the patch and see if there are any rejects.

If so,  then ignore the patch file (it has done it's job) and modify the relevant source files that the patch made changes to.

Once it compiles cleanly, then do the diff to a (differently-named) .patch file in order to re-submit to Flyspray.

It's a bit confusing, but you'll get there in the end.

If all else fails, you can always do the revert -R command to remove all local edits and get back to a clean copy.

[Llorean]

'make clean' just cleans up the build directory. It doesn't compile a build using clean sources.

svn revert -r * in your source directory (the same place you run svn update from) will revert any and all changes, after which a normal make will be 'clean' as it were.

[digerati1338]

You are correct, except for the reverse-apply.

You apply the patch and see if there are any rejects.

If so,  then ignore the patch file (it has done it's job) and modify the relevant source files that the patch made changes to.

Once it compiles cleanly, then do the diff to a (differently-named) .patch file in order to re-submit to Flyspray.

It's a bit confusing, but you'll get there in the end.

If all else fails, you can always do the revert -R command to remove all local edits and get back to a clean copy.

Thanks.  This is exactly what I was looking for.