Fixes conflict block rendering bug.

src/vs/editor/browser/viewParts/blockDecorations/blockDecorations.ts

@@ -82,10 +82,20 @@ export class BlockDecorations extends ViewPart {
 				block = this.blocks[count] = createFastDomNode(document.createElement('div'));
 				this.domNode.appendChild(block);
 			}
-			const top = ctx.getVerticalOffsetForLineNumber(decoration.range.startLineNumber, true);
-			const bottom = decoration.range.isEmpty()
-				? ctx.getVerticalOffsetForLineNumber(decoration.range.startLineNumber, false)
-				: ctx.getVerticalOffsetAfterLineNumber(decoration.range.endLineNumber, true);
+
+			let top: number;
+			let bottom: number;
+
+			if (decoration.options.blockIsAfterEnd) {
+				// range must be empty
+				top = ctx.getVerticalOffsetAfterLineNumber(decoration.range.endLineNumber, false);
+				bottom = ctx.getVerticalOffsetAfterLineNumber(decoration.range.endLineNumber, true);
+			} else {
+				top = ctx.getVerticalOffsetForLineNumber(decoration.range.startLineNumber, true);
+				bottom = decoration.range.isEmpty()
+					? ctx.getVerticalOffsetForLineNumber(decoration.range.startLineNumber, false)
+					: ctx.getVerticalOffsetAfterLineNumber(decoration.range.endLineNumber, true);
+			}
 
 			block.setClassName('blockDecorations-block ' + decoration.options.blockClassName);
 			block.setLeft(ctx.scrollLeft);

src/vs/editor/common/model.ts

@@ -92,6 +92,11 @@ export interface IModelDecorationOptions {
 	 */
 	className?: string | null;
 	blockClassName?: string | null;
+	/**
+	 * Indicates if this block should be rendered after the last line.
+	 * In this case, the range must be empty and set to the last line.
+	 */
+	blockIsAfterEnd?: boolean | null;
 	/**
 	 * Message to be rendered when hovering over the glyph margin decoration.
 	 */

src/vs/editor/common/model/textModel.ts

@@ -2231,6 +2231,7 @@ export class ModelDecorationOptions implements model.IModelDecorationOptions {
 
 	readonly description: string;
 	readonly blockClassName: string | null;
+	readonly blockIsAfterEnd: boolean | null;
 	readonly stickiness: model.TrackedRangeStickiness;
 	readonly zIndex: number;
 	readonly className: string | null;
@@ -2258,6 +2259,7 @@ export class ModelDecorationOptions implements model.IModelDecorationOptions {
 	private constructor(options: model.IModelDecorationOptions) {
 		this.description = options.description;
 		this.blockClassName = options.blockClassName ? cleanClassName(options.blockClassName) : null;
+		this.blockIsAfterEnd = options.blockIsAfterEnd ?? null;
 		this.stickiness = options.stickiness || model.TrackedRangeStickiness.AlwaysGrowsWhenTypingAtEdges;
 		this.zIndex = options.zIndex || 0;
 		this.className = options.className ? cleanClassName(options.className) : null;

src/vs/monaco.d.ts

@@ -1488,6 +1488,11 @@ declare namespace monaco.editor {
 		 */
 		className?: string | null;
 		blockClassName?: string | null;
+		/**
+		 * Indicates if this block should be rendered after the last line.
+		 * In this case, the range must be empty and set to the last line.
+		 */
+		blockIsAfterEnd?: boolean | null;
 		/**
 		 * Message to be rendered when hovering over the glyph margin decoration.
 		 */

src/vs/workbench/contrib/mergeEditor/browser/view/editors/inputCodeEditorView.ts

@@ -158,6 +158,7 @@ export class InputCodeEditorView extends CodeEditorView {
 				options: {
 					showIfCollapsed: true,
 					blockClassName: blockClassNames.join(' '),
+					blockIsAfterEnd: range.startLineNumber > this.editor.getModel()!.getLineCount(),
 					description: 'Merge Editor',
 					minimap: {
 						position: MinimapPosition.Gutter,