8251167: Drawing polyline twice in XOR mode leaves out some traces on…

… screen (only with uiScale=1.0)

src/java.desktop/macosx/native/libawt_lwawt/java2d/metal/MTLRenderQueue.m

@@ -414,19 +414,33 @@ void MTLRenderQueue_CheckPreviousOp(jint op) {
         case sun_java2d_pipe_BufferedOpCodes_DRAW_POLY:
             {
                 CHECK_PREVIOUS_OP(MTL_OP_OTHER);
-
-                if ([mtlc useXORComposite]) {
-                    commitEncodedCommands();
-                    J2dTraceLn(J2D_TRACE_VERBOSE, "DRAW_POLY in XOR mode - Force commit earlier draw calls before DRAW_POLY.");
-                }
-
                 jint nPoints      = NEXT_INT(b);
                 jboolean isClosed = NEXT_BOOLEAN(b);
                 jint transX       = NEXT_INT(b);
                 jint transY       = NEXT_INT(b);
                 jint *xPoints = (jint *)b;
                 jint *yPoints = ((jint *)b) + nPoints;
-                MTLRenderer_DrawPoly(mtlc, dstOps, nPoints, isClosed, transX, transY, xPoints, yPoints);
+
+                if ([mtlc useXORComposite]) {
+                    commitEncodedCommands();
+                    J2dTraceLn(J2D_TRACE_VERBOSE, "DRAW_POLY in XOR mode - Force commit earlier draw calls before DRAW_POLY.");
+
+                    // draw separate (N-1) lines using N points
+                    for(int point = 0; point < nPoints-1; point++) {
+                        jint x1 = xPoints[point] + transX;
+                        jint y1 = yPoints[point] + transY;
+                        jint x2 = xPoints[point + 1] + transX;
+                        jint y2 = yPoints[point + 1] + transY;
+                        MTLRenderer_DrawLine(mtlc, dstOps, x1, y1, x2, y2);
+                    }
+
+                    if (isClosed) {
+                        MTLRenderer_DrawLine(mtlc, dstOps, xPoints[0] + transX, yPoints[0] + transY, xPoints[nPoints-1] + transX, yPoints[nPoints-1] + transY);
+                    }
+                } else {
+                    MTLRenderer_DrawPoly(mtlc, dstOps, nPoints, isClosed, transX, transY, xPoints, yPoints);
+                }
+
                 SKIP_BYTES(b, nPoints * BYTES_PER_POLY_POINT);
             }
             break;