[bug-gettext] [PATCH] Support explicit string concatenation with '+' in Python.

[Daiki Ueno]

---
 gettext-tools/src/x-python.c          | 76 ++++++++++++++++++++++++++++-------
 gettext-tools/tests/xgettext-python-1 |  8 ++++
 2 files changed, 70 insertions(+), 14 deletions(-)

diff --git a/gettext-tools/src/x-python.c b/gettext-tools/src/x-python.c
index aa6a7d6..cdca255 100644
--- a/gettext-tools/src/x-python.c
+++ b/gettext-tools/src/x-python.c
@@ -1,5 +1,5 @@
 /* xgettext Python backend.
-   Copyright (C) 2002-2003, 2005-2011 Free Software Foundation, Inc.
+   Copyright (C) 2002-2003, 2005-2013 Free Software Foundation, Inc.
 
    This file was written by Bruno Haible <address@hidden>, 2002.
 
@@ -994,6 +994,7 @@ enum token_type_ty
   token_type_rbracket,          /* ] */
   token_type_string,            /* "abc", 'abc', """abc""", '''abc''' */
   token_type_symbol,            /* symbol, number */
+  token_type_plus,              /* + */
   token_type_other              /* misc. operator */
 };
 typedef enum token_type_ty token_type_ty;
@@ -1007,6 +1008,16 @@ struct token_ty
   int line_number;
 };
 
+/* Free the memory pointed to by a 'struct token_ty'.  */
+static inline void
+free_token (token_ty *tp)
+{
+  if (tp->type == token_type_string || tp->type == token_type_symbol)
+    free (tp->string);
+  if (tp->type == token_type_string)
+    drop_reference (tp->comment);
+}
+
 
 /* There are two different input syntaxes for strings, "abc" and r"abc",
    and two different input syntaxes for Unicode strings, u"abc" and ur"abc".
@@ -1594,6 +1605,10 @@ phase5_get (token_ty *tp)
           tp->type = (c == ']' ? token_type_rbracket : token_type_other);
           return;
 
+        case '+':
+          tp->type = token_type_plus;
+          return;
+
         default:
           /* We could carefully recognize each of the 2 and 3 character
              operators, but it is not necessary, as we only need to recognize
@@ -1625,23 +1640,55 @@ static void
 x_python_lex (token_ty *tp)
 {
   phase5_get (tp);
-  if (tp->type != token_type_string)
-    return;
-  for (;;)
+  if (tp->type == token_type_string)
     {
-      token_ty tmp;
-      size_t len;
+      char *sum = tp->string;
+      size_t sum_len = strlen (sum);
 
-      phase5_get (&tmp);
-      if (tmp.type != token_type_string)
+      for (;;)
         {
-          phase5_unget (&tmp);
-          return;
+          token_ty token2, *tp2 = NULL;
+
+          phase5_get (&token2);
+          switch (token2.type)
+            {
+            case token_type_plus:
+              {
+                token_ty token3;
+
+                phase5_get (&token3);
+                if (token3.type == token_type_string)
+                  {
+                    free_token (&token2);
+                    tp2 = &token3;
+                  }
+                else
+                  phase5_unget (&token3);
+              }
+              break;
+            case token_type_string:
+              tp2 = &token2;
+              break;
+            default:
+              break;
+            }
+
+          if (tp2)
+            {
+              char *addend = tp2->string;
+              size_t addend_len = strlen (addend);
+
+              sum = (char *) xrealloc (sum, sum_len + addend_len + 1);
+              memcpy (sum + sum_len, addend, addend_len + 1);
+              sum_len += addend_len;
+
+              free_token (tp2);
+              continue;
+            }
+          phase5_unget (&token2);
+          break;
         }
-      len = strlen (tp->string);
-      tp->string = xrealloc (tp->string, len + strlen (tmp.string) + 1);
-      strcpy (tp->string + len, tmp.string);
-      free (tmp.string);
+      tp->string = sum;
     }
 }
 
@@ -1817,6 +1864,7 @@ extract_balanced (message_list_ty *mlp,
           xgettext_current_source_encoding = 
xgettext_current_file_source_encoding;
           return true;
 
+        case token_type_plus:
         case token_type_other:
           next_context_iter = null_context_list_iterator;
           state = 0;
diff --git a/gettext-tools/tests/xgettext-python-1 
b/gettext-tools/tests/xgettext-python-1
index 20ea53e..a649b3d 100755
--- a/gettext-tools/tests/xgettext-python-1
+++ b/gettext-tools/tests/xgettext-python-1
@@ -25,6 +25,10 @@ _(ur"abc\
 
 # This will not be extracted.
 _(CATEGORIES["default"]["name"]);
+
+# string concatenation
+_("abc" "def" + "ghi"
+"jkl")
 EOF
 
 tmpfiles="$tmpfiles xg-py-1.err xg-py-1.tmp xg-py-1.pot"
@@ -80,6 +84,10 @@ msgid ""
 "\\\\def\\'ghi\\\"jkl\\a\\b\\f\\n\\r\\t\\v 
x\\040x\\x7ey$(D)H(B\\U00010123\\N{LATIN "
 "SMALL LETTER Z}"
 msgstr ""
+
+#. string concatenation
+msgid "abcdefghijkl"
+msgstr ""
 EOF
 
 : ${DIFF=diff}
-- 
1.8.1.4