Merge pull request #21859 from delftswa2017/21600-clearing-search-results

proposal to fix issue 21600

src/vs/base/common/history.ts

@@ -23,6 +23,12 @@ export class HistoryNavigator<T> implements INavigator<T> {
 		this._onChange();
 	}
 
+	public addIfNotPresent(t: T) {
+		if (!this._history.contains(t)) {
+			this.add(t);
+		}
+	}
+
 	public next(): T {
 		if (this._navigator.next()) {
 			return this._navigator.current();
@@ -67,4 +73,5 @@ export class HistoryNavigator<T> implements INavigator<T> {
 			this._history = new ArraySet<T>(data.slice(data.length - this._limit));
 		}
 	}
+
 }
\ No newline at end of file

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

@@ -170,7 +170,13 @@ export class SearchWidget extends Widget {
 	}
 
 	public showPreviousSearchTerm() {
-		let previous = this.searchHistory.previous();
+		let previous;
+		if (this.searchInput.getValue().length === 0) {
+			previous = this.searchHistory.current();
+		} else {
+			this.searchHistory.addIfNotPresent(this.searchInput.getValue());
+			previous = this.searchHistory.previous();
+		}
 		if (previous) {
 			this.searchInput.setValue(previous);
 		}