diff tests/test-diff-inverse @ 9725:3f522d2fa633

diff: add --inverse option

Most of the time, one can reverse a diff by swapping the revisions passed with
-r but it happens that if you use the global -R, and diff against the tip of
the current repo, you can't swap the revisions. One use-case for that is
reviewing changes from a bundle before unbundling. One could also pipe the
output of `hg diff` to a command line filter that reverses the diff, but that
would remove the benefit from color diffs. Therefore, having an option in
`hg diff` to reverse a diff is a good thing.

The option flag selection was tricky. GNU patch uses -R/--reverse but -R is
already used as a global option and --reverse would make --rev ambiguous.

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/tests/test-diff-inverse	Thu Nov 05 15:18:56 2009 +0100
@@ -0,0 +1,24 @@
+#!/bin/sh
+
+hg init
+cat > a <<EOF
+a
+b
+c
+EOF
+hg ci -Am adda
+
+cat > a <<EOF
+d
+e
+f
+EOF
+hg ci -m moda
+
+hg diff --inverse -r0 -r1
+
+cat >> a <<EOF
+g
+h
+EOF
+hg diff --inverse --nodates