Fix #58374

src/vs/workbench/parts/search/browser/searchView.ts

@@ -1078,6 +1078,13 @@ export class SearchView extends Viewlet implements IViewlet, IPanel {
 		const excludePattern = this.inputPatternExcludes.getValue();
 		const includePattern = this.inputPatternIncludes.getValue();
 
+		// Need the full match line to correctly calculate replace text, if this is a search/replace with regex group references ($1, $2, ...).
+		// 10000 chars is enough to avoid sending huge amounts of text around, if you do a replace with a longer match, it may or may not resolve the group refs correctly.
+		// https://github.com/Microsoft/vscode/issues/58374
+		const totalChars = content.isRegExp ? 10000 :
+			this.isWide ? 250 :
+				75;
+
 		const options: IQueryOptions = {
 			extraFileResources: getOutOfWorkspaceEditorResources(this.editorService, this.contextService),
 			maxResults: SearchView.MAX_TEXT_RESULTS,
@@ -1088,7 +1095,7 @@ export class SearchView extends Viewlet implements IViewlet, IPanel {
 			previewOptions: {
 				leadingChars: 20,
 				maxLines: 1,
-				totalChars: this.isWide ? 250 : 75
+				totalChars
 			}
 		};
 		const folderResources = this.contextService.getWorkspace().folders;

src/vs/workbench/parts/search/common/searchModel.ts

@@ -27,6 +27,8 @@ import { IReplaceService } from 'vs/workbench/parts/search/common/replace';
 
 export class Match {
 
+	private static readonly MAX_PREVIEW_CHARS = 250;
+
 	private _id: string;
 	private _range: Range;
 	private _previewText: string;
@@ -66,10 +68,15 @@ export class Match {
 	}
 
 	public preview(): { before: string; inside: string; after: string; } {
-		const before = this._previewText.substring(0, this._rangeInPreviewText.startColumn - 1),
+		let before = this._previewText.substring(0, this._rangeInPreviewText.startColumn - 1),
 			inside = this.getMatchString(),
 			after = this._previewText.substring(this._rangeInPreviewText.endColumn - 1);
 
+		let charsRemaining = Match.MAX_PREVIEW_CHARS - before.length;
+		inside = inside.substr(0, charsRemaining);
+		charsRemaining -= inside.length;
+		after = after.substr(0, charsRemaining);
+
 		return {
 			before,
 			inside,