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
diff -r acd8075edac9 b
--- /dev/null
+++ b/b
@@ -0,0 +1,1 @@
+123
diff -r acd8075edac9 b
--- /dev/null
+++ b/b
@@ -0,0 +1,1 @@
+123
diff -r acd8075edac9 a
--- a/a
+++ b/a
@@ -0,0 +1,1 @@
+foo
diff -r acd8075edac9 b
--- /dev/null
+++ b/b
@@ -0,0 +1,1 @@
+123
abort: 00changelog.i@: ambiguous identifier!
abort: 00changelog.i@: ambiguous identifier!