Fix invalid handling of global RegExps (fixes #143).

src/api/selections.ts

@@ -721,12 +721,28 @@ export function splitSelections(re: RegExp, selections = Context.current.selecti
 /**
  * Returns the selections obtained by finding all the matches within the given
  * selections using the given RegExp.
+ *
+ * ### Example
+ *
+ * ```ts
+ * expect(Selections.selectWithin(/\d/).map(text), "to equal", [
+ *   "1",
+ *   "2",
+ *   "6",
+ *   "7",
+ *   "8",
+ * ]);
+ * ```
+ *
+ * With:
+ * ```
+ * a1b2c3d4
+ * ^^^^^ 0
+ * e5f6g7h8
+ *   ^^^^^^ 1
+ * ```
  */
 export function selectWithinSelections(re: RegExp, selections = Context.current.selections) {
-  if (!re.global) {
-    re = new RegExp(re.source, re.flags + "g");
-  }
-
   const document = Context.current.document;
 
   return Selections.map((text, selection) => {

src/commands/search.ts

@@ -40,11 +40,11 @@ export function search(
   setInput: SetInput<RegExp>,
 ) {
   return manipulateSelectionsInteractively(_, input, setInput, interactive, {
-    ...prompt.regexpOpts("mug"),
+    ...prompt.regexpOpts("mu"),
     value: lastSearchInput?.source,
   }, (input, selections) => {
     if (typeof input === "string") {
-      input = new RegExp(input, "mug");
+      input = new RegExp(input, "mu");
     }
 
     lastSearchInput = input;

src/utils/regexp.ts

@@ -1656,6 +1656,8 @@ export function splitRange(text: string, re: RegExp) {
   const sections: [start: number, end: number][] = [];
 
   for (let start = 0;;) {
+    re.lastIndex = 0;
+
     const match = re.exec(text);
 
     if (match === null || text.length === 0) {
@@ -1673,8 +1675,6 @@ export function splitRange(text: string, re: RegExp) {
       text = text.slice(match.index + match[0].length);
       start += match.index + match[0].length;
     }
-
-    re.lastIndex = 0;
   }
 }
 
@@ -1683,6 +1683,8 @@ export function splitRange(text: string, re: RegExp) {
  * indices corresponding to each matched result.
  */
 export function execRange(text: string, re: RegExp) {
+  re.lastIndex = 0;
+
   const sections: [start: number, end: number, match: RegExpExecArray][] = [];
   let diff = 0;
 
@@ -1694,6 +1696,7 @@ export function execRange(text: string, re: RegExp) {
 
     text = text.slice(end);
     diff += end;
+    re.lastIndex = 0;
 
     if (start === end) {
       text = text.slice(1);

test/suite/api.test.ts

@@ -1009,6 +1009,31 @@ suite("API tests", function () {
       // No expected end document.
     });
 
+    test("function selectWithinSelections", async function () {
+      const editorState = extension.editors.getState(editor)!,
+            context = new Context(editorState, cancellationToken),
+            before = ExpectedDocument.parseIndented(14, String.raw`
+              a1b2c3d4
+              ^^^^^ 0
+              e5f6g7h8
+                ^^^^^^ 1
+            `);
+
+      await before.apply(editor);
+
+      await context.runAsync(async () => {
+        expect(Selections.selectWithin(/\d/).map(text), "to equal", [
+          "1",
+          "2",
+          "6",
+          "7",
+          "8",
+        ]);
+      });
+
+      // No expected end document.
+    });
+
     test("function mergeOverlappingSelections", async function () {
       const editorState = extension.editors.getState(editor)!,
             context = new Context(editorState, cancellationToken),