Fix non-default backgrounds on left cell of wide/overlapping chars

Fixes #1031

src/renderer/BaseRenderLayer.ts

@@ -224,11 +224,6 @@ export abstract class BaseRenderLayer implements IRenderLayer {
    * @param bold Whether the text is bold.
    */
   protected drawChar(terminal: ITerminal, char: string, code: number, width: number, x: number, y: number, fg: number, bg: number, bold: boolean): void {
-    // Clear the cell next to this character if it's wide
-    if (width === 2) {
-      this.clearCells(x + 1, y, 1, 1);
-    }
-
     let colorIndex = 0;
     if (fg < 256) {
       colorIndex = fg + 2;

src/renderer/TextRenderLayer.ts

@@ -146,6 +146,11 @@ export class TextRenderLayer extends BaseRenderLayer {
           }
         }
 
+        // Clear the cell next to this character if it's wide
+        if (width === 2) {
+          this.clearCells(x + 1, y, 1, 1);
+        }
+
         // Draw background
         if (bg < 256) {
           this._ctx.save();