[Annotation] Strip out the array index in the path only when the path is from a terminal node (bug 1847733)

src/core/annotation.js

@@ -1630,7 +1630,8 @@ class WidgetAnnotation extends Annotation {
     if (
       data.fieldName &&
       /\[\d+\]$/.test(data.fieldName) &&
-      !dict.has("Kids")
+      !dict.has("Kids") &&
+      dict.has("T")
     ) {
       data.baseFieldName = data.fieldName.substring(
         0,

src/core/document.js

@@ -1711,7 +1711,7 @@ class PDFDocument {
       name = name === "" ? partName : `${name}.${partName}`;
     }
 
-    if (!field.has("Kids") && /\[\d+\]$/.test(name)) {
+    if (!field.has("Kids") && field.has("T") && /\[\d+\]$/.test(name)) {
       // We've a terminal node: strip the index.
       name = name.substring(0, name.lastIndexOf("["));
     }

test/integration/annotation_spec.js

@@ -160,6 +160,37 @@ describe("Checkbox annotation", () => {
       );
     });
   });
+
+  describe("bug1847733.pdf", () => {
+    let pages;
+
+    beforeAll(async () => {
+      pages = await loadAndWait("bug1847733.pdf", "[data-annotation-id='18R']");
+    });
+
+    afterAll(async () => {
+      await closePages(pages);
+    });
+
+    it("must check the checkbox", async () => {
+      await Promise.all(
+        pages.map(async ([browserName, page]) => {
+          const selectors = [18, 30, 42, 54].map(
+            id => `[data-annotation-id='${id}R']`
+          );
+          for (const selector of selectors) {
+            await page.click(selector);
+            page.waitForTimeout(10);
+          }
+          for (const selector of selectors) {
+            await page.waitForFunction(
+              `document.querySelector("${selector} > :first-child").checked`
+            );
+          }
+        })
+      );
+    });
+  });
 });
 
 describe("Text widget", () => {

test/pdfs/bug1847733.pdf.link

@@ -0,0 +1,2 @@
+https://github.com/mozilla/pdf.js/files/12290354/PDF.Form.4.pdf
+

test/test_manifest.json

@@ -8070,5 +8070,13 @@
       "rounds": 1,
       "type": "eq",
       "print": true
+   },
+   {
+      "id": "bug1847733",
+      "file": "pdfs/bug1847733.pdf",
+      "md5": "d2e167216493a50f732b4b3685a91792",
+      "rounds": 1,
+      "link": true,
+      "type": "other"
    }
 ]