On Tue, 14 Aug 2007, Thomas Gleixner wrote: > > is there a built in way to handle the following situation: > > file A is renamed to B > file A is created again and new content is added. That "should just work". [ However, there does seem to be a bug in the "-B" logic, so it doesn't actually work as well as it should! See below ] BUT! By default, rename detection isn't on at all, mostly because it results in patches that non-git "patch" cannot apply, but partly also because it can slow certain things down. So to get nice diffs, use git show -B -C where the magic is: - "-B" means "break file associations when a file is *too* dissimilar" Normally, git will assume that if a filename stays around, it's the same file. However, with "-B", it does similarity analysis even for files that are the same, and if they are very different, git will decide that maybe they weren't the same file after all! - "-C" is "find code movement and copying". However, nobody ever actually uses "-B" (it's so rare as to effectively not exist, and it does slow things down a bit), so it seems to have bit-rotted (or maybe it had this bug even originally: as I said, I don't think anybody has ever really _used_ this functionality). Junio, look at this: # create a repo in "testing" cd mkdir testing cd testing/ git init # copy a file from the git repo cp ~/git/revision.c . git add revision.c git commit -a -m "Add file 'A'" # move it around, copy another file in its stead git mv revision.c old-revision.c cp ~/git/Makefile revision.c git add revision.c git commit -a -m "Move file 'A' to 'B', create new 'A'" git show -B -C and notice how "-B" *did* actually work, and we get a nice: diff --git a/revision.c b/old-revision.c similarity index 100% rename from revision.c rename to old-revision.c but then it breaks: instead of creating the new "revision.c", we get: diff --git a/revision.c b/revision.c dissimilarity index 98% index 038693c..4eb4637 100644 --- a/revision.c +++ b/revision.c @@ -1,1572 +1,1117 @@ -#include "cache.h" ... which uses "reivision.c" as the base, even though it was already broken up! I think it *should* have looked like diff --git a/old-revision.c b/old-revision.c new file mode 100644 index 0000000..4eb4637 --- /dev/null +++ b/revision.c +# The default target of this Makefile is... ... so I think there is a bug there where the "-B" thing doesn't really "stick", and some part still uses the old file content even though it was dis-associated with the new content! Hmm? Linus - To unsubscribe from this list: send the line "unsubscribe git" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
