On Oct 21, 2010, at 2:47 PM, Joshua Jensen wrote: > It has become a necessity to copy a file from one long-lived branch to another. It is not possible to merge the branches at this time. > > I would like to have 'git gui blame' follow the copy back through its original history, but I don't believe Git has metadata for storing this. Something along the lines of a 'followparent' in the commit object, for instance, would allow the revision walking code to wander the history down an alternate line. Git stores no per-file metadata. The closest we come is .gitattributes and .gitignore. > By comparison, integrates work at a file level in Perforce. That means I can integrate a file from one branch to another, and parentage is stored such that I can follow the file back through its history. > > Are there any facilities to do this now? Git simply does not have the idea of the history of a file. Nothing in git will help merge "just a file" from one branch to another. Either we have merged the two commits or not. HOWEVER... You can use git-filter-branch to create a new branch that contains only that single file and only the commits that affected it. Something like the following (untested): # Merging "file" from branch "src" to branch "dest" git checkout -b temp src git filter-branch --prune-empty --index-filter="git read-tree --empty; git add file" # Since you describe the branch as "long-running", I'd suspect you'll have to wait a while here. git checkout dest git merge temp git branch -d temp git branch -D refs/original/temp This will go faster if you have a ramdisk/tmpfs to perform the filtering in. (git-filter-branch is very I/O intensive.) Something like the following in place of the `git filter-branch` invocation above: mkdir /tmp/filter-branch # Assuming /tmp is tmpfs or similar git filter-branch -d /tmp/filter-branch --prune-empty --index-filter="git read-tree --empty; git add file" rm -rf /tmp/filter-branch You could use --msg-filter to add the SHA-1 of the original commits to the "file history" branch. Something like --msg-filter='cat;echo;echo From: $GIT_COMMIT' I would recommend using cherry-pick to pull any further changes to the file across branches (be careful of commits that touch more than that file!). I think git-filter-branch could be used to keep the one file branch up to date, but that is likely more effort than it's worth. I would specifically advise against merging the single file branch into both "src" and "dest", as I think any later merge of the two would find these commits as a merge-base. ~~ Brian Gernhardt -- 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