# HG changeset patch
# User Anton Shestakov <av6@dwimlabs.net>
# Date 1535462921 -28800
# Node ID c0fbe70f2e482b0c599b8d12454450ac35716487
# Parent  503ae2689df81e19aeb5121d7422b2c5af631f41
topic: check that repo.currenttopic is set before using it as an argument

repo.currenttopic can be an empty string, which means there's no current topic
set. This fact can be used to short-circuit some checks.

Also, this avoids passing an empty string as an argument to topic() revset.

diff -r 503ae2689df8 -r c0fbe70f2e48 hgext3rd/topic/__init__.py
--- a/hgext3rd/topic/__init__.py	Wed Aug 29 18:59:07 2018 +0200
+++ b/hgext3rd/topic/__init__.py	Tue Aug 28 21:28:41 2018 +0800
@@ -644,9 +644,9 @@
 
     ct = repo.currenttopic
     if clear:
-        empty = stack.stack(repo, topic=ct).changesetcount == 0
-        if empty:
-            if ct:
+        if ct:
+            empty = stack.stack(repo, topic=ct).changesetcount == 0
+            if empty:
                 ui.status(_('clearing empty topic "%s"\n') % ct)
         return _changecurrenttopic(repo, None)
 
@@ -1149,7 +1149,6 @@
         # rebased commit. We have explicitly stored in config if rebase is
         # running.
         ot = repo.currenttopic
-        empty = stack.stack(repo, topic=ot).changesetcount == 0
         if repo.ui.hasconfig('experimental', 'topicrebase'):
             isrebase = True
         if repo.ui.configbool('_internal', 'keep-topic'):
@@ -1163,8 +1162,10 @@
                 f.write(t)
             if t and t != ot:
                 repo.ui.status(_("switching to topic %s\n") % t)
-            if ot and not t and empty:
-                repo.ui.status(_('clearing empty topic "%s"\n') % ot)
+            if ot and not t:
+                empty = stack.stack(repo, topic=ot).changesetcount == 0
+                if empty:
+                    repo.ui.status(_('clearing empty topic "%s"\n') % ot)
         elif ist0:
             repo.ui.status(_("preserving the current topic '%s'\n") % ot)
         return ret
diff -r 503ae2689df8 -r c0fbe70f2e48 hgext3rd/topic/destination.py
--- a/hgext3rd/topic/destination.py	Wed Aug 29 18:59:07 2018 +0200
+++ b/hgext3rd/topic/destination.py	Tue Aug 28 21:28:41 2018 +0800
@@ -59,7 +59,10 @@
     """decide on an update destination from current topic"""
     movemark = node = None
     topic = repo.currenttopic
-    revs = repo.revs('.::topic("%s")' % topic)
+    if topic:
+        revs = repo.revs('.::topic(%s)', topic)
+    else:
+        revs = []
     if not revs:
         return None, None, None
     node = revs.last()