templater: handle None returned from templatedir()

My recent 91aa9bba3dc9 (templater: make templatepaths() return a
single path, or None, 2020-07-21) didn't account for the fact that
`templatedir()` returns `None` in frozen binaries. That is ironic,
since the reason I'm working on this is to add support for built-in
mapfiles in frozen binaries. This patch updates the callers to handle
the `None` case. It's somewhat ugly, but I will have to revisit this
soon anyway, since my goal is to make all callers handle that case by
trying to read the map file using the resources API instead.

Differential Revision: https://phab.mercurial-scm.org/D8810

mercurial/debugcommands.py

@@ -1669,7 +1669,7 b' def debuginstall(ui, **opts):'
 
     # templates
     p = templater.templatedir()
-    fm.write(b'templatedirs', b'checking templates (%s)...\n', p)
+    fm.write(b'templatedirs', b'checking templates (%s)...\n', p or b'')
     fm.condwrite(not p, b'', _(b" no template directories found\n"))
     if p:
         m = templater.templatepath(b"map-cmdline.default")

mercurial/hgweb/hgwebdir_mod.py

@@ -415,7 +415,8 b' class hgwebdir(object):'
                 static = self.ui.config(b"web", b"static", untrusted=False)
                 if not static:
                     tp = self.templatepath or templater.templatedir()
-                    static = [os.path.join(tp, b'static')]
+                    if tp is not None:
+                        static = [os.path.join(tp, b'static')]
 
                 staticfile(static, fname, res)
                 return res.sendresponse()

mercurial/templater.py

@@ -828,6 +828,8 b' def _readmapfile(mapfile):'
     def include(rel, abs, remap, sections):
         templatedirs = [base, templatedir()]
         for dir in templatedirs:
+            if dir is None:
+                continue
             abs = os.path.normpath(os.path.join(dir, rel))
             if os.path.isfile(abs):
                 data = util.posixfile(abs, b'rb').read()
@@ -850,13 +852,15 b' def _readmapfile(mapfile):'
 
         # fallback check in template paths
         if not os.path.exists(path):
-            p2 = util.normpath(os.path.join(templatedir(), val))
-            if os.path.isfile(p2):
-                path = p2
-            else:
-                p3 = util.normpath(os.path.join(p2, b"map"))
-                if os.path.isfile(p3):
-                    path = p3
+            dir = templatedir()
+            if dir is not None:
+                p2 = util.normpath(os.path.join(dir, val))
+                if os.path.isfile(p2):
+                    path = p2
+                else:
+                    p3 = util.normpath(os.path.join(p2, b"map"))
+                    if os.path.isfile(p3):
+                        path = p3
 
         cache, tmap, aliases = _readmapfile(path)
 
@@ -1064,6 +1068,9 b' def templatedir():'
 
 def templatepath(name):
     '''return location of template file. returns None if not found.'''
+    dir = templatedir()
+    if dir is None:
+        return None
     f = os.path.join(templatedir(), name)
     if f and os.path.exists(f):
         return f
@@ -1085,22 +1092,23 b' def stylemap(styles, path=None):'
     if isinstance(styles, bytes):
         styles = [styles]
 
-    for style in styles:
-        # only plain name is allowed to honor template paths
-        if (
-            not style
-            or style in (pycompat.oscurdir, pycompat.ospardir)
-            or pycompat.ossep in style
-            or pycompat.osaltsep
-            and pycompat.osaltsep in style
-        ):
-            continue
-        locations = [os.path.join(style, b'map'), b'map-' + style]
-        locations.append(b'map')
+    if path is not None:
+        for style in styles:
+            # only plain name is allowed to honor template paths
+            if (
+                not style
+                or style in (pycompat.oscurdir, pycompat.ospardir)
+                or pycompat.ossep in style
+                or pycompat.osaltsep
+                and pycompat.osaltsep in style
+            ):
+                continue
+            locations = [os.path.join(style, b'map'), b'map-' + style]
+            locations.append(b'map')
 
-        for location in locations:
-            mapfile = os.path.join(path, location)
-            if os.path.isfile(mapfile):
-                return style, mapfile
+            for location in locations:
+                mapfile = os.path.join(path, location)
+                if os.path.isfile(mapfile):
+                    return style, mapfile
 
     raise RuntimeError(b"No hgweb templates found in %r" % path)