add some tests for qpush/qpop error codes

tests/test-mq

@@ -169,6 +169,46 b' echo % push should succeed'
 hg qpop -a
 hg push ../../k
 
+echo % qpush/qpop error codes
+errorcode()
+{
+    hg "$@" && echo "  $@ succeeds" || echo "  $@ fails"
+}
+
+# we want to start with some patches applied
+hg qpush -a
+echo "  % pops all patches and succeeds"
+errorcode qpop -a
+echo "  % does nothing and succeeds"
+errorcode qpop -a
+echo "  % fails - nothing else to pop"
+errorcode qpop
+echo "  % pushes a patch and succeeds"
+errorcode qpush
+echo "  % pops a patch and succeeds"
+errorcode qpop
+echo "  % pushes up to test1b.patch and succeeds"
+errorcode qpush test1b.patch
+echo "  % does nothing and succeeds"
+errorcode qpush test1b.patch
+echo "  % does nothing and succeeds"
+errorcode qpop test1b.patch
+echo "  % fails - can't push to this patch"
+errorcode qpush test.patch
+echo "  % fails - can't pop to this patch"
+errorcode qpop test2.patch
+echo "  % pops up to test.patch and succeeds"
+errorcode qpop test.patch
+echo "  % pushes all patches and succeeds"
+errorcode qpush -a
+echo "  % does nothing and succeeds"
+errorcode qpush -a
+echo "  % fails - nothing else to push"
+errorcode qpush
+echo "  % does nothing and succeeds"
+errorcode qpush test2.patch
+
+
 echo % strip
 cd ../../b
 echo x>x

tests/test-mq.out

@@ -156,6 +156,61 b' adding changesets'
 adding manifests
 adding file changes
 added 1 changesets with 1 changes to 1 files
+% qpush/qpop error codes
+applying test.patch
+applying test1b.patch
+applying test2.patch
+Now at: test2.patch
+  % pops all patches and succeeds
+Patch queue now empty
+  qpop -a succeeds
+  % does nothing and succeeds
+no patches applied
+  qpop -a succeeds
+  % fails - nothing else to pop
+no patches applied
+  qpop fails
+  % pushes a patch and succeeds
+applying test.patch
+Now at: test.patch
+  qpush succeeds
+  % pops a patch and succeeds
+Patch queue now empty
+  qpop succeeds
+  % pushes up to test1b.patch and succeeds
+applying test.patch
+applying test1b.patch
+Now at: test1b.patch
+  qpush test1b.patch succeeds
+  % does nothing and succeeds
+qpush: test1b.patch is already at the top
+  qpush test1b.patch succeeds
+  % does nothing and succeeds
+qpop: test1b.patch is already at the top
+  qpop test1b.patch succeeds
+  % fails - can't push to this patch
+abort: cannot push to a previous patch: test.patch
+  qpush test.patch fails
+  % fails - can't pop to this patch
+abort: patch test2.patch is not applied
+  qpop test2.patch fails
+  % pops up to test.patch and succeeds
+Now at: test.patch
+  qpop test.patch succeeds
+  % pushes all patches and succeeds
+applying test1b.patch
+applying test2.patch
+Now at: test2.patch
+  qpush -a succeeds
+  % does nothing and succeeds
+all patches are currently applied
+  qpush -a succeeds
+  % fails - nothing else to push
+patch series already fully applied
+  qpush fails
+  % does nothing and succeeds
+all patches are currently applied
+  qpush test2.patch succeeds
 % strip
 adding x
 0 files updated, 0 files merged, 1 files removed, 0 files unresolved