Mercurial diff not working after move/rename
diff, dvcs, mercurial, rename, version-control
Solution
This is difficult or impossible with today's Mercurial. I think the closest you can get is
hg log --follow --patch -r 1 a
where Mercurial will track the copies backwards (`--follow`) before showing the diff (`--patch`).
In general, Mercurial does not track file identities, it only tracks file names. When you lookup information by revision number, Mercurial will first lookup the revision, and then lookup any filenames in that revision. So `hg cat -r 0 a` will give you the same result as
hg update -r 0
cat a
i.e., the result is independent of the current working directory parent.
Problem
After moving a file into another directory I cannot display the differences between two revisions any more. E.g.: ``` hg init touch a hg add a hg ci -m "Added a" echo "Bli" >> a hg ci -m "Bli" echo "Bla" >> a hg ci -m "Bla" echo "Blub" >> a hg ci -m "Blub" hg diff -r 0 -r 1 a ``` Results in: ``` diff -r 8603b08f5a64 -r 16675581549e a --- a/a Mon Apr 23 09:03:25 2012 +0000 +++ b/a Mon Apr 23 09:03:25 2012 +0000 @@ -0,0 +1,1 @@ +Bli ``` which is what I expected. However when I now move the file "a" into a directory "b": ``` mkdir b hg mv a b/a hg ci -m "Moved a into b" cd b hg diff -r 0 -r 1 a ``` this results into nothing (no output at all). I also tried to use the git Giff algo: ``` hg diff --git -r 0 -r 1 a ``` Again, there is no output at all. The log is seems to be OK: ``` hg log --follow a ``` Results in: ``` changeset: 4:cb8185829bfd tag: tip user: XXXXXXXXXXXXXXXXXXXXXXXXXXXX date: Mon Apr 23 09:08:12 2012 +0000 summary: Moved a into b changeset: 3:4d1ba89885c3 user: XXXXXXXXXXXXXXXXXXXXXXXXXXXX date: Mon Apr 23 09:03:26 2012 +0000 summary: Blub changeset: 2:e9126dbb50b2 user: XXXXXXXXXXXXXXXXXXXXXXXXXXXX date: Mon Apr 23 09:03:26 2012 +0000 summary: Bla changeset: 1:16675581549e user: XXXXXXXXXXXXXXXXXXXXXXXXXXXX date: Mon Apr 23 09:03:25 2012 +0000 summary: Bli changeset: 0:8603b08f5a64 user: XXXXXXXXXXXXXXXXXXXXXXXXXXXX date: Mon Apr 23 09:03:25 2012 +0000 summary: Added a ``` Has someone any idea why the diff is not working after moving a file? Your help is greatly appreciated.