From 823d375b8b979680a0932f3e199a76fbdb453ac8 Mon Sep 17 00:00:00 2001
From: Jonas Jenwald <jonas.jenwald@gmail.com>
Date: Fri, 10 Nov 2023 12:49:37 +0100
Subject: [PATCH] Ensure that the viewer waits for the library to complete
 loading (issue 17228)

This should *hopefully* fix 17228, by tweaking the build scripts to give the GENERIC viewer something to await to avoid breaking third-party users of the standalone viewer components.
---
 gulpfile.mjs | 2 +-
 web/pdfjs.js | 9 +++++++++
 2 files changed, 10 insertions(+), 1 deletion(-)

diff --git a/gulpfile.mjs b/gulpfile.mjs
index 2de6f1f8b..55bc5f001 100644
--- a/gulpfile.mjs
+++ b/gulpfile.mjs
@@ -422,7 +422,7 @@ function tweakWebpackOutput(jsName) {
       case " __webpack_exports__ = {};":
         return ` __webpack_exports__ = globalThis.${jsName} = {};`;
       case " __webpack_exports__ = await __webpack_exports__;":
-        return ` __webpack_exports__ = globalThis.${jsName} = await __webpack_exports__;`;
+        return ` __webpack_exports__ = globalThis.${jsName} = await (globalThis.${jsName}Promise = __webpack_exports__);`;
     }
     return match;
   });
diff --git a/web/pdfjs.js b/web/pdfjs.js
index 3ca9b5490..30da7c8d6 100644
--- a/web/pdfjs.js
+++ b/web/pdfjs.js
@@ -13,6 +13,15 @@
  * limitations under the License.
  */
 
+// Ensure that the viewer waits for the library to complete loading,
+// to avoid breaking e.g. the standalone viewer components (see issue 17228).
+if (
+  (typeof PDFJSDev === "undefined" || PDFJSDev.test("GENERIC")) &&
+  !globalThis.pdfjsLib
+) {
+  await globalThis.pdfjsLibPromise;
+}
+
 const {
   AbortException,
   AnnotationEditorLayer,