Bug 1178955 - Print line number for parse errors; r=smacleod

It helps users debug problems.

--HG--
extra : commitid : IU6Cw35FEiM
extra : rebase_source : f6ab1ef356bb10b689f2fed034a9f2564ffe0fc3
extra : amend_source : ef52d60ca12796fcfe32392077a7606628a54d29

tools/mercurial/hgsetup/config.py

@@ -31,7 +31,9 @@ def config_file(files):
 
 
 class ParseException(Exception):
-    pass
+    def __init__(self, line, msg):
+        self.line = line
+        super(Exception, self).__init__(msg)
 
 
 class MercurialConfig(object):
@@ -47,12 +49,12 @@ class MercurialConfig(object):
         # error saying this.
         if os.path.exists(path):
             with codecs.open(path, 'r', encoding='utf-8') as f:
-                for line in f:
+                for i, line in enumerate(f):
                     if line.startswith('%include'):
-                        raise ParseException(
+                        raise ParseException(i + 1,
                             '%include directive is not supported by MercurialConfig')
                     if line.startswith(';'):
-                        raise ParseException(
+                        raise ParseException(i + 1,
                             'semicolon (;) comments are not supported; '
                             'use # instead')
 

tools/mercurial/hgsetup/wizard.py

@@ -229,7 +229,7 @@ class MercurialSetupWizard(object):
             return 1
         except ParseException as e:
             print('Error importing existing Mercurial config: %s\n' % config_path)
-            print(e.message)
+            print('Line %d: %s' % (e.line, e.message))
 
             return 1