templater: factor out helper that renders named template as string

This is quite common in non-web templating, and **kwargs expansion is annoying
because of the unicode-ness of Python3.

mercurial/formatter.py

@@ -401,9 +401,7 b' class templateformatter(baseformatter):'
         if 'ctx' in item or 'fctx' in item:
             # but template resources must be always available
             props['revcache'] = {}
-        props = pycompat.strkwargs(props)
-        g = self._t(ref, **props)
-        self._out.write(templateutil.stringify(g))
+        self._out.write(self._t.render(ref, props))
 
     def end(self):
         baseformatter.end(self)

mercurial/hgweb/hgweb_mod.py

@@ -30,7 +30,6 b' from .. import ('
     repoview,
     templatefilters,
     templater,
-    templateutil,
     ui as uimod,
     util,
     wireprotoserver,
@@ -378,8 +377,8 b' class hgweb(object):'
 
         try:
             rctx.tmpl = rctx.templater(req)
-            ctype = rctx.tmpl('mimetype', encoding=encoding.encoding)
-            ctype = templateutil.stringify(ctype)
+            ctype = rctx.tmpl.render('mimetype',
+                                     {'encoding': encoding.encoding})
 
             # check read permissions non-static content
             if cmd != 'static':

mercurial/hgweb/hgwebdir_mod.py

@@ -35,7 +35,6 b' from .. import ('
     pycompat,
     scmutil,
     templater,
-    templateutil,
     ui as uimod,
     util,
 )
@@ -381,8 +380,7 b' class hgwebdir(object):'
 
             virtual = req.dispatchpath.strip('/')
             tmpl = self.templater(req, nonce)
-            ctype = tmpl('mimetype', encoding=encoding.encoding)
-            ctype = templateutil.stringify(ctype)
+            ctype = tmpl.render('mimetype', {'encoding': encoding.encoding})
 
             # Global defaults. These can be overridden by any handler.
             res.status = '200 Script output follows'

mercurial/logcmdutil.py

@@ -33,7 +33,6 b' from . import ('
     smartset,
     templatekw,
     templater,
-    templateutil,
     util,
 )
 from .utils import dateutil
@@ -450,15 +449,13 b' class changesettemplater(changesetprinte'
             self._parts.update(m)
 
         if self._parts['docheader']:
-            self.ui.write(
-                templateutil.stringify(self.t(self._parts['docheader'])))
+            self.ui.write(self.t.render(self._parts['docheader'], {}))
 
     def close(self):
         if self._parts['docfooter']:
             if not self.footer:
                 self.footer = ""
-            self.footer += templateutil.stringify(
-                self.t(self._parts['docfooter']))
+            self.footer += self.t.render(self._parts['docfooter'], {})
         return super(changesettemplater, self).close()
 
     def _show(self, ctx, copies, props):
@@ -467,18 +464,16 b' class changesettemplater(changesetprinte'
         props['ctx'] = ctx
         props['index'] = index = next(self._counter)
         props['revcache'] = {'copies': copies}
-        props = pycompat.strkwargs(props)
 
         # write separator, which wouldn't work well with the header part below
         # since there's inherently a conflict between header (across items) and
         # separator (per item)
         if self._parts['separator'] and index > 0:
-            self.ui.write(
-                templateutil.stringify(self.t(self._parts['separator'])))
+            self.ui.write(self.t.render(self._parts['separator'], {}))
 
         # write header
         if self._parts['header']:
-            h = templateutil.stringify(self.t(self._parts['header'], **props))
+            h = self.t.render(self._parts['header'], props)
             if self.buffered:
                 self.header[ctx.rev()] = h
             else:
@@ -488,13 +483,12 b' class changesettemplater(changesetprinte'
 
         # write changeset metadata, then patch if requested
         key = self._parts[self._tref]
-        self.ui.write(templateutil.stringify(self.t(key, **props)))
+        self.ui.write(self.t.render(key, props))
         self._showpatch(ctx)
 
         if self._parts['footer']:
             if not self.footer:
-                self.footer = templateutil.stringify(
-                    self.t(self._parts['footer'], **props))
+                self.footer = self.t.render(self._parts['footer'], props)
 
 def templatespec(tmpl, mapfile):
     if mapfile:

mercurial/templater.py

@@ -725,8 +725,12 b' class templater(object):'
 
     def renderdefault(self, mapping):
         """Render the default unnamed template and return result as string"""
+        return self.render('', mapping)
+
+    def render(self, t, mapping):
+        """Render the specified named template and return result as string"""
         mapping = pycompat.strkwargs(mapping)
-        return templateutil.stringify(self('', **mapping))
+        return templateutil.stringify(self(t, **mapping))
 
     def __call__(self, t, **mapping):
         mapping = pycompat.byteskwargs(mapping)