# HG changeset patch
# User Ryan McElroy <rmcelroy@fb.com>
# Date 2014-06-13 01:07:21
# Node ID 028a481051919e3c985261ac62606704435f9c6a
# Parent  4a445dc5abff7f0e971222bea1bf04ce02bead5e

templater: add symbol to error

This patch makes it easier to debug writing templater functions by
telling the user exactly what was sent to the templater.

diff --git a/mercurial/templater.py b/mercurial/templater.py
--- a/mercurial/templater.py
+++ b/mercurial/templater.py
@@ -111,7 +111,7 @@ def compileexp(exp, context):
 def getsymbol(exp):
     if exp[0] == 'symbol':
         return exp[1]
-    raise error.ParseError(_("expected a symbol"))
+    raise error.ParseError(_("expected a symbol, got '%s'") % exp[0])
 
 def getlist(x):
     if not x:
diff --git a/tests/test-command-template.t b/tests/test-command-template.t
--- a/tests/test-command-template.t
+++ b/tests/test-command-template.t
@@ -1911,3 +1911,9 @@ Test startswith
   |
   o  line 1
      line 2
+
+Test bad template with better error message
+
+  $ hg log -Gv -R a --template '{desc|user()}'
+  hg: parse error: expected a symbol, got 'func'
+  [255]