templater: fix precedence of --style and --template options

Since e3eb480a9391, --template option is ignored if --style is specified,
which is wrong according to the doc of show_changeset():

    Display format will be the first non-empty hit of:
    1. option 'template'
    2. option 'style'
    ...

mercurial/cmdutil.py

@@ -1087,7 +1087,7 b' def gettemplate(ui, tmpl, style):'
     """
 
     # ui settings
-    if not tmpl and not style:
+    if not tmpl and not style: # template are stronger than style
         tmpl = ui.config('ui', 'logtemplate')
         if tmpl:
             try:
@@ -1098,7 +1098,7 b' def gettemplate(ui, tmpl, style):'
         else:
             style = util.expandpath(ui.config('ui', 'style', ''))
 
-    if style:
+    if not tmpl and style:
         mapfile = style
         if not os.path.split(mapfile)[0]:
             mapname = (templater.templatepath('map-cmdline.' + mapfile)

tests/test-command-template.t

@@ -86,6 +86,11 b' Test templates and style maps in files:'
   $ hg log -l1 -T./map-simple
   8
 
+Template should precede style option
+
+  $ hg log -l1 --style default -T '{rev}\n'
+  8
+
 Default style is like normal output:
 
   $ hg log > log.out