string.c: skip invalid char gap

* string.c (enc_succ_alnum_char): try to skip an invalid character
  gap between GREEK CAPITAL RHO and SIGMA.
  [ruby-core:74478] [Bug #12204]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@54210 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

ChangeLog

@@ -1,3 +1,9 @@
+Mon Mar 21 19:09:31 2016  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* string.c (enc_succ_alnum_char): try to skip an invalid character
+	  gap between GREEK CAPITAL RHO and SIGMA.
+	  [ruby-core:74478] [Bug #12204]
+
 Mon Mar 21 18:55:49 2016  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* node.c (rb_gc_mark_node): NODE_MATCH2 can have nd_args, u3,

string.c

@@ -3552,6 +3552,10 @@ enc_succ_alnum_char(char *p, long len, rb_encoding *enc, char *carry)
     int range;
     char save[ONIGENC_CODE_TO_MBC_MAXLEN];
 
+    /* skip 03A2, invalid char between GREEK CAPITAL LETTERS */
+    int try;
+    const int max_gaps = 1;
+
     c = rb_enc_mbc_to_codepoint(p, p+len, enc);
     if (rb_enc_isctype(c, ONIGENC_CTYPE_DIGIT, enc))
         ctype = ONIGENC_CTYPE_DIGIT;
@@ -3561,12 +3565,14 @@ enc_succ_alnum_char(char *p, long len, rb_encoding *enc, char *carry)
         return NEIGHBOR_NOT_CHAR;
 
     MEMCPY(save, p, char, len);
+    for (try = 0; try <= max_gaps; ++try) {
 	ret = enc_succ_char(p, len, enc);
 	if (ret == NEIGHBOR_FOUND) {
 	    c = rb_enc_mbc_to_codepoint(p, p+len, enc);
 	    if (rb_enc_isctype(c, ctype, enc))
 		return NEIGHBOR_FOUND;
 	}
+    }
     MEMCPY(p, save, char, len);
     range = 1;
     while (1) {

test/ruby/test_m17n.rb

@@ -1678,4 +1678,9 @@ class TestM17N < Test::Unit::TestCase
     end
     assert_equal(e("[\"\xB4\xC1\xBB\xFA\"]"), s, bug11787)
   end
+
+  def test_greek_capital_gap
+    bug12204 = '[ruby-core:74478] [Bug #12204] GREEK CAPITAL RHO and SIGMA'
+    assert_equal("\u03A3", "\u03A1".succ, bug12204)
+  end
 end