Get reflow smaller working for wide chars

src/Buffer.ts

@@ -429,7 +429,7 @@ export class Buffer implements IBuffer {
       let destCol = destLineLengths[destLineIndex]; // cellsNeeded % newCols;
       if (destCol === 0) {
         destLineIndex--;
-        destCol = newCols;
+        destCol = destLineLengths[destLineIndex];
       }
       let srcLineIndex = wrappedLines.length - linesToAdd - 1;
       let srcCol = lastLineLength;
@@ -449,6 +449,13 @@ export class Buffer implements IBuffer {
         }
       }
 
+      // Null out the end of the line ends if a wide character wrapped to the following line
+      for (let i = 0; i < wrappedLines.length; i++) {
+        if (destLineLengths[i] < newCols) {
+          wrappedLines[i].set(destLineLengths[i], FILL_CHAR_DATA);
+        }
+      }
+
       // Adjust viewport as needed
       let viewportAdjustments = linesToAdd - trimmedLines;
       while (viewportAdjustments-- > 0) {