jruby_diff.java

diff --git a/core/src/main/java/org/jruby/RubyRegexp.java b/core/src/main/java/org/jruby/RubyRegexp.java
index a86ab9da95..42af190df0 100755
--- a/core/src/main/java/org/jruby/RubyRegexp.java
+++ b/core/src/main/java/org/jruby/RubyRegexp.java
@@ -1136,14 +1136,12 @@ public class RubyRegexp extends RubyObject implements ReOptions, EncodingCapable
 
     @JRubyMethod(name = "match?")
     public IRubyObject match_p(ThreadContext context, IRubyObject str) {
-        IRubyObject[] dummy = new IRubyObject[1];
-        return context.runtime.newBoolean(matchPos(context, str, null, dummy, 0) >= 0);
+        return matchP(context, str, 0);
     }
 
     @JRubyMethod(name = "match?")
     public IRubyObject match_p(ThreadContext context, IRubyObject str, IRubyObject pos) {
-        IRubyObject[] dummy = new IRubyObject[1];
-        return context.runtime.newBoolean(matchPos(context, str, null, dummy, RubyNumeric.num2int(pos)) >= 0);
+        return matchP(context, str, RubyNumeric.num2int(pos));
     }
 
     private IRubyObject matchCommon(ThreadContext context, IRubyObject str, int pos, boolean setBackref, Block block) {
@@ -1183,6 +1181,53 @@ public class RubyRegexp extends RubyObject implements ReOptions, EncodingCapable
         return search(context, str, pos, false, holder);
     }
 
+    private RubyBoolean matchP(ThreadContext context, IRubyObject arg, int pos) {
+        if (arg == context.nil) return context.fals;
+        RubyString str = arg instanceof RubySymbol ? ((RubySymbol) arg).to_s(context.runtime) : arg.convertToString();
+
+        if (pos != 0) {
+            if (pos < 0) {
+                pos += str.strLength();
+                if (pos < 0) return context.fals;
+            }
+            pos = str.rbStrOffset(pos);
+        }
+
+        final Regex reg = preparePattern(str);
+        final boolean tmpreg = reg != this.pattern;
+        if (!tmpreg) this.useCount++;
+
+        final ByteList strBL = str.getByteList();
+        final int beg = strBL.begin();
+
+        Matcher matcher = reg.matcherNoRegion(strBL.unsafeBytes(), beg, beg + strBL.realSize());
+
+        int result = -1;
+        JOniException exception = null;
+        try {
+            result = matcherSearch(context, matcher, beg + pos, beg + strBL.realSize(), RE_OPTION_NONE);
+        } catch (JOniException je) {
+            exception = je;
+        }
+
+        if (tmpreg) {
+            if (this.useCount > 0) {
+            } else {
+                this.pattern = reg;
+            }
+        } else {
+            this.useCount--;
+        }
+
+        if (result < 0) {
+            if (result == -1) {
+                return context.fals;
+            }
+            throw context.runtime.newRegexpError(exception == null ? "FIXME: missing message" : exception.getMessage());
+        }
+        return context.tru;
+    }
+
     /**
      * MRI: rb_reg_search
      *