fix: report filename if template file is invalid

A file name like .#issue.search.html causes a crash because _find
returns None not a tuple and unpacking fails.

Trap the TypeError and raise ValueError with message that includes the
basename of the file.

Author: rouilj

roundup/cgi/engine_chameleon.py

@@ -14,7 +14,12 @@ def __init__(self, template_dir):
         self.loader = chameleon.PageTemplateLoader(template_dir)
 
     def load(self, tplname):
-        src, filename = self._find(tplname)
+        try:
+            src, filename = self._find(tplname)
+        except TypeError as e:
+            raise ValueError("Unable to load template file basename: %s: %s" % (
+                tplname, e))
+
         return RoundupPageTemplate(self.loader.load(src))
 
 

roundup/cgi/engine_zopetal.py

@@ -22,7 +22,11 @@ def __init__(self, template_dir):
 
     def load(self, tplname):
         # find the source
-        src, filename = self._find(tplname)
+        try:
+            src, filename = self._find(tplname)
+        except TypeError as e:
+            raise ValueError("Unable to load template file basename: %s: %s" % (
+                tplname, e))
 
         # has it changed?
         try: