Making your branches smaller for easier merges

["Daniel Berlin" <dberlin at dberlin dot org>]

I see occasional complaints about the size of mainline merges to
branches  Most people working on branches are only modifying a very
small subset of the files that are in mainline, and certainly not the
entire trunk tree.

You guys should be aware that you can simply branch those files you
want (or those subdir trees you want), and keep the rest at the same
revision as the mainline.

IE you can have

/branches/my-branch-gccdir -> copy of only /trunk/gcc

and use svn switch to switch just your gcc subdirectory to this, while
keeping all the other subdirs as mainline.

svn knows how to handle this, and will properly keep everything at the
right revisions.

svnmerge knows how to handle this case, and you will avoid having to
do merges of large dirs like libjava, libstdc++, etc at all.

If you are just writing a new pass, you can probably get away with
branching only a few files, and switching those may be a lot better
strategy than branching the entire trunk tree branch to modify 6 files
in the gcc dir.