diff -r b6cc68ef2702 -r 30b5e83004e0 tests/test-diff-change.t
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/tests/test-diff-change.t	Mon Aug 30 14:38:15 2010 +0200
@@ -0,0 +1,86 @@
+Testing diff --change
+
+  $ hg init a
+  $ cd a
+
+  $ echo "first" > file.txt
+  $ hg add file.txt
+  $ hg commit -m 'first commit' # 0
+
+  $ echo "second" > file.txt
+  $ hg commit -m 'second commit' # 1
+
+  $ echo "third" > file.txt
+  $ hg commit -m 'third commit' # 2
+
+  $ hg diff --nodates --change 1
+  diff -r 4bb65dda5db4 -r e9b286083166 file.txt
+  --- a/file.txt
+  +++ b/file.txt
+  @@ -1,1 +1,1 @@
+  -first
+  +second
+
+  $ hg diff --change e9b286083166
+  diff -r 4bb65dda5db4 -r e9b286083166 file.txt
+  --- a/file.txt	Thu Jan 01 00:00:00 1970 +0000
+  +++ b/file.txt	Thu Jan 01 00:00:00 1970 +0000
+  @@ -1,1 +1,1 @@
+  -first
+  +second
+
+
+Testing diff --change when merge:
+
+  $ for i in 1 2 3 4 5 6 7 8 9 10; do
+  $    echo $i >> file.txt
+  $ done
+  $ hg commit -m "lots of text" # 3
+
+  $ sed -e 's,^2$,x,' file.txt > file.txt.tmp
+  $ mv file.txt.tmp file.txt
+  $ hg commit -m "change 2 to x" # 4
+
+  $ hg up -r 3
+  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
+  $ sed -e 's,^8$,y,' file.txt > file.txt.tmp
+  $ mv file.txt.tmp file.txt
+  $ hg commit -m "change 8 to y"
+  created new head
+
+  $ hg up -C -r 4
+  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
+  $ hg merge -r 5
+  merging file.txt
+  0 files updated, 1 files merged, 0 files removed, 0 files unresolved
+  (branch merge, don't forget to commit)
+  $ hg commit -m "merge 8 to y" # 6
+
+  $ hg diff --change 5
+  diff -r ae119d680c82 -r 9085c5c02e52 file.txt
+  --- a/file.txt	Thu Jan 01 00:00:00 1970 +0000
+  +++ b/file.txt	Thu Jan 01 00:00:00 1970 +0000
+  @@ -6,6 +6,6 @@
+   5
+   6
+   7
+  -8
+  +y
+   9
+   10
+
+must be similar to 'hg diff --change 5':
+
+  $ hg diff -c 6
+  diff -r 273b50f17c6d -r 979ca961fd2e file.txt
+  --- a/file.txt	Thu Jan 01 00:00:00 1970 +0000
+  +++ b/file.txt	Thu Jan 01 00:00:00 1970 +0000
+  @@ -6,6 +6,6 @@
+   5
+   6
+   7
+  -8
+  +y
+   9
+   10
+