string.c: search by rb_str_index

* re.c (match_regexp): set regexp for MatchData from string.
* re.c (rb_backref_set_string): create MatchData from string and
  set backref.
* string.c (rb_pat_search, rb_str_sub, rb_str_sub_bang, str_gsub),
  (scan_once, rb_str_scan, rb_str_partition): use rb_str_index
  instead of rb_reg_search() when pattern is a String.  based on
  the patch by Sam Rawlins <sam.rawlins@gmail.com> [Fixes GH-579]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@45451 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 37 insertions, 1 deletions

diff --git a/re.c b/re.c
index 54ba47c199..5927e9e9f3 100644
--- a/re.c
+++ b/re.c
@@ -1017,8 +1017,15 @@ match_init_copy(VALUE obj, VALUE orig)
 static VALUE
 match_regexp(VALUE match)
 {
+    VALUE regexp;
     match_check(match);
-    return RMATCH(match)->regexp;
+    regexp = RMATCH(match)->regexp;
+    if (NIL_P(regexp)) {
+	VALUE str = rb_reg_nth_match(0, match);
+	regexp = rb_reg_regcomp(rb_reg_quote(str));
+	RMATCH(match)->regexp = regexp;
+    }
+    return regexp;
 }
 
 /*
@@ -1216,6 +1223,31 @@ rb_match_busy(VALUE match)
     FL_SET(match, MATCH_BUSY);
 }
 
+static void
+match_set_string(VALUE m, VALUE string, long pos, long len)
+{
+    struct RMatch *match = (struct RMatch *)m;
+    struct rmatch *rmatch = match->rmatch;
+
+    match->str = string;
+    match->regexp = Qnil;
+    onig_region_resize(&rmatch->regs, 1);
+    rmatch->regs.beg[0] = pos;
+    rmatch->regs.end[0] = pos + len;
+    rmatch->char_offset_updated = 0;
+}
+
+void
+rb_backref_set_string(VALUE string, long pos, long len)
+{
+    VALUE match = rb_backref_get();
+    if (NIL_P(match) || FL_TEST(match, MATCH_BUSY)) {
+	match = match_alloc(rb_cMatch);
+    }
+    match_set_string(match, string, pos, len);
+    rb_backref_set(match);
+}
+
 /*
  *  call-seq:
  *     rxp.fixed_encoding?   -> true or false
@@ -1909,6 +1941,10 @@ match_inspect(VALUE match)
     if (regexp == 0) {
         return rb_sprintf("#<%"PRIsVALUE":%p>", cname, (void*)match);
     }
+    else if (NIL_P(regexp)) {
+        return rb_sprintf("#<%"PRIsVALUE": %"PRIsVALUE">",
+			  cname, rb_reg_nth_match(0, match));
+    }
 
     names = ALLOCA_N(struct backref_name_tag, num_regs);
     MEMZERO(names, struct backref_name_tag, num_regs);