Fix #57705

src/vs/workbench/parts/preferences/electron-browser/preferencesSearch.ts

@@ -191,8 +191,16 @@ class RemoteSearchProvider implements ISearchProvider {
 			const highScore = highScoreKey ? remoteResult.scoredResults[highScoreKey].score : 0;
 			const minScore = highScore / 5;
 			if (this.options.newExtensionsOnly) {
+				return this.installedExtensions.then(installedExtensions => {
 					const newExtsMinScore = Math.max(RemoteSearchProvider.NEW_EXTENSIONS_MIN_SCORE, minScore);
-				const passingScoreKeys = resultKeys.filter(k => remoteResult.scoredResults[k].score >= newExtsMinScore);
+					const passingScoreKeys = resultKeys
+						.filter(k => {
+							const result = remoteResult.scoredResults[k];
+							const resultExtId = (result.extensionPublisher + '.' + result.extensionName).toLowerCase();
+							return !installedExtensions.some(ext => ext.galleryIdentifier.id.toLowerCase() === resultExtId);
+						})
+						.filter(k => remoteResult.scoredResults[k].score >= newExtsMinScore);
+
 					const filterMatches: ISettingMatch[] = passingScoreKeys.map(k => {
 						const remoteSetting = remoteResult.scoredResults[k];
 						const setting = remoteSettingToISetting(remoteSetting);
@@ -207,6 +215,7 @@ class RemoteSearchProvider implements ISearchProvider {
 						filterMatches,
 						metadata: remoteResult
 					};
+				});
 			} else {
 				const settingMatcher = this.getRemoteSettingMatcher(remoteResult.scoredResults, minScore, preferencesModel);
 				const filterMatches = preferencesModel.filterSettings(this.options.filter, group => null, settingMatcher);