mq: support "qimport --existing --name renametothis thatexistingpatch"
Before this change, the command would abort with a not too clear "patch
renametothis does not exist" error.
This change makes:
qimport --existing --name renametothis thatexistingpatch
equivalent to:
qimport --existing thatexistingpatch; qrename thatexistingpatch renametothis
adding a
diff -r 2855cdcfcbb7 -r 8e1805a3cf6e a
--- a/a Thu Jan 01 00:00:00 1970 +0000
+++ b/a Thu Jan 01 00:00:00 1970 +0000
@@ -1,3 +1,3 @@
-d
-e
-f
+a
+b
+c
diff -r 2855cdcfcbb7 a
--- a/a
+++ b/a
@@ -1,5 +1,3 @@
d
e
f
-g
-h