Fixes #43238: Do not comput brackets if the cursor count is too high

src/vs/editor/contrib/bracketMatching/bracketMatching.ts

@@ -281,6 +281,14 @@ export class BracketMatchingController extends Disposable implements editorCommo
 			return;
 		}
 
+		const selections = this._editor.getSelections();
+		if (selections.length > 100) {
+			// no bracket matching for high numbers of selections
+			this._lastBracketsData = [];
+			this._lastVersionId = 0;
+			return;
+		}
+
 		const model = this._editor.getModel();
 		const versionId = model.getVersionId();
 		let previousData: BracketsData[] = [];
@@ -289,8 +297,6 @@ export class BracketMatchingController extends Disposable implements editorCommo
 			previousData = this._lastBracketsData;
 		}
 
-		const selections = this._editor.getSelections();
-
 		let positions: Position[] = [], positionsLen = 0;
 		for (let i = 0, len = selections.length; i < len; i++) {
 			let selection = selections[i];