templater: make label() take unknown symbol as color literal

templater: make label() take unknown symbol as color literal

Instead of the mapping hack introduced by b775a2029e8d, this patch changes the
way how a label symbol is evaluated. This is still hackish, but should be more
predictable in that it doesn't depend on the known color effects.

This change is intended to eliminate the reference to color._effects so that
color.templatelabel() can be merged with templater.label().

--- a/hgext/color.py	Wed Mar 02 15:50:34 2016 +0000
+++ b/hgext/color.py	Thu Jun 11 22:58:27 2015 +0900
@@ -485,10 +485,6 @@
         # i18n: "label" is a keyword
         raise error.ParseError(_("label expects two arguments"))
 
-    # add known effects to the mapping so symbols like 'red', 'bold',
-    # etc. don't need to be quoted
-    mapping.update(dict([(k, k) for k in _effects]))
-
     thing = templater.evalstring(context, mapping, args[1])
 
     # apparently, repo could be a string that is the favicon?
@@ -496,7 +492,9 @@
     if isinstance(repo, str):
         return thing
 
-    label = templater.evalstring(context, mapping, args[0])
+    # preserve unknown symbol as literal so effects like 'red', 'bold',
+    # etc. don't need to be quoted
+    label = templater.evalstringliteral(context, mapping, args[0])
 
     return repo.ui.label(thing, label)
 

--- a/mercurial/templater.py	Wed Mar 02 15:50:34 2016 +0000
+++ b/mercurial/templater.py	Thu Jun 11 22:58:27 2015 +0900
@@ -231,6 +231,16 @@
     func, data = arg
     return stringify(func(context, mapping, data))
 
+def evalstringliteral(context, mapping, arg):
+    """Evaluate given argument as string template, but returns symbol name
+    if it is unknown"""
+    func, data = arg
+    if func is runsymbol:
+        thing = func(context, mapping, data, default=data)
+    else:
+        thing = func(context, mapping, data)
+    return stringify(thing)
+
 def runinteger(context, mapping, data):
     return int(data)
 
@@ -245,7 +255,7 @@
 def _runrecursivesymbol(context, mapping, key):
     raise error.Abort(_("recursive reference '%s' in template") % key)
 
-def runsymbol(context, mapping, key):
+def runsymbol(context, mapping, key, default=''):
     v = mapping.get(key)
     if v is None:
         v = context._defaults.get(key)
@@ -257,7 +267,7 @@
         try:
             v = context.process(key, safemapping)
         except TemplateNotFound:
-            v = ''
+            v = default
     if callable(v):
         return v(**mapping)
     return v

--- a/tests/test-command-template.t	Wed Mar 02 15:50:34 2016 +0000
+++ b/tests/test-command-template.t	Thu Jun 11 22:58:27 2015 +0900
@@ -3178,6 +3178,11 @@
   $ hg log --color=always -l 1 --template '{label("text.{rev}", "text\n")}'
   \x1b[0;32mtext\x1b[0m (esc)
 
+color effect can be specified without quoting:
+
+  $ hg log --color=always -l 1 --template '{label(red, "text\n")}'
+  \x1b[0;31mtext\x1b[0m (esc)
+
 Test branches inside if statement:
 
   $ hg log -r 0 --template '{if(branches, "yes", "no")}\n'