templater: fix escaping in nested string literals (issue4102) stable

templater: fix escaping in nested string literals (issue4102)

Before the templater got extended for nested expressions, it made
sense to decode string escapes across the whole string. Now we do it
on a piece by piece basis.

--- a/mercurial/cmdutil.py	Thu Nov 07 20:36:26 2013 -0800
+++ b/mercurial/cmdutil.py	Mon Nov 18 14:02:26 2013 -0500
@@ -940,9 +940,7 @@
 
     tmpl = opts.get('template')
     style = None
-    if tmpl:
-        tmpl = templater.parsestring(tmpl, quoted=False)
-    else:
+    if not tmpl:
         style = opts.get('style')
 
     # ui settings

--- a/mercurial/templater.py	Thu Nov 07 20:36:26 2013 -0800
+++ b/mercurial/templater.py	Mon Nov 18 14:02:26 2013 -0500
@@ -52,7 +52,7 @@
                     if not decode:
                         yield ('string', program[s:pos].replace('\\', r'\\'), s)
                         break
-                    yield ('string', program[s:pos].decode('string-escape'), s)
+                    yield ('string', program[s:pos], s)
                     break
                 pos += 1
             else:
@@ -80,19 +80,19 @@
     parsed = []
     pos, stop = 0, len(tmpl)
     p = parser.parser(tokenizer, elements)
-
     while pos < stop:
         n = tmpl.find('{', pos)
         if n < 0:
-            parsed.append(("string", tmpl[pos:]))
+            parsed.append(("string", tmpl[pos:].decode("string-escape")))
             break
         if n > 0 and tmpl[n - 1] == '\\':
             # escaped
-            parsed.append(("string", tmpl[pos:n - 1] + "{"))
+            parsed.append(("string",
+                           (tmpl[pos:n - 1] + "{").decode("string-escape")))
             pos = n + 1
             continue
         if n > pos:
-            parsed.append(("string", tmpl[pos:n]))
+            parsed.append(("string", tmpl[pos:n].decode("string-escape")))
 
         pd = [tmpl, n + 1, stop]
         parseres, pos = p.parse(pd)

--- a/mercurial/templates/paper/shortlog.tmpl	Thu Nov 07 20:36:26 2013 -0800
+++ b/mercurial/templates/paper/shortlog.tmpl	Mon Nov 18 14:02:26 2013 -0500
@@ -80,8 +80,8 @@
                 return m ? m[1] : null;
             },
             '.bigtable > tbody:nth-of-type(2)',
-            '<tr class="%class%">\
-            <td colspan="3" style="text-align: center;">%text%</td>\
+            '<tr class="%class%">\\
+            <td colspan="3" style="text-align: center;">%text%</td>\\
             </tr>'
     );
 </script>

--- a/tests/test-command-template.t	Thu Nov 07 20:36:26 2013 -0800
+++ b/tests/test-command-template.t	Mon Nov 18 14:02:26 2013 -0500
@@ -1586,3 +1586,11 @@
   h1c
   b
   a
+
+Test string escaping:
+
+  $ hg log -R latesttag -r 0 --template '>\n<>\\n<{if(rev, "[>\n<>\\n<]")}>\n<>\\n<\n'
+  >
+  <>\n<[>
+  <>\n<]>
+  <>\n<