tor-browser

commit 17b8f2f85bc2d35f13375d2dde45e7c23203d483
parent ae9c610377718bc0cae69d32519e23eb2daadea4
Author: Julian Descottes <jdescottes@mozilla.com>
Date:   Thu,  8 Jan 2026 11:05:30 +0000

Bug 2004973 - [devtools] Chunk calls to String.fromCharCode in NetworkUtils r=devtools-reviewers,bomsy

Need to chunk calls to String.fromCharCode because data might be a very large array.

Differential Revision: https://phabricator.services.mozilla.com/D277897

Diffstat:
M
devtools/shared/network-observer/NetworkUtils.sys.mjs
 | 
10
+++++++++-
M
devtools/shared/network-observer/test/browser/browser_networkobserver_response_body_limit.js
 | 
52
+++++++++++++++++++++++++++++++++++-----------------

2 files changed, 44 insertions(+), 18 deletions(-)
diff --git a/devtools/shared/network-observer/NetworkUtils.sys.mjs b/devtools/shared/network-observer/NetworkUtils.sys.mjs
@@ -867,7 +867,15 @@ async function decodeCompressedStream(stream, length, encodings) {
         _length,
         data
       ) {
-        resolve(String.fromCharCode.apply(this, data));
+        // `data`` might be a very large array, chunk calls to fromCharCode to
+        // avoid "RangeError: too many arguments provided for a function call".
+        const CHUNK_SIZE = 65536;
+        let result = "";
+        for (let i = 0; i < data.length; i += CHUNK_SIZE) {
+          const chunk = data.slice(i, i + CHUNK_SIZE);
+          result += String.fromCharCode.apply(null, chunk);
+        }
+        resolve(result);
       },
     });
   });
diff --git a/devtools/shared/network-observer/test/browser/browser_networkobserver_response_body_limit.js b/devtools/shared/network-observer/test/browser/browser_networkobserver_response_body_limit.js
@@ -51,6 +51,7 @@ const BYTES_1000 = 1000;
 const smallSize = BYTES_1000 / 2;
 const bigSize = BYTES_1000 * 2;
 const hugeSize = BYTES_1000 * 20;
+const tooManyArgumentsSize = BYTES_1000 * 1000;
 
 add_task(async function testNetworkObserverWithResponseBodyLimit1000() {
   info("Test a network observer with specific response body limit (1000)");
@@ -126,23 +127,40 @@ add_task(async function testNetworkObserverWithResponseBodyLimitZero() {
   info("Test a network observer with a response body limit = zero (unlimited)");
   const tab = await addTab(TEST_URL);
 
-  const events = [];
-  const noLimitNetworkObserver = createNetworkObserver({
-    events,
-    responseBodyLimit: 0,
-    decodeResponseBodies: true,
-  });
-
-  await performGetDataRequest(gBrowser, events, smallSize);
-  await assertNetworkEventContent(events.at(-1), smallSize, false);
-
-  await performGetDataRequest(gBrowser, events, bigSize);
-  await assertNetworkEventContent(events.at(-1), bigSize, false);
-
-  await performGetDataRequest(gBrowser, events, hugeSize);
-  await assertNetworkEventContent(events.at(-1), hugeSize, false);
-
-  noLimitNetworkObserver.destroy();
+  for (const useGzip of [true, false]) {
+    for (const decodeResponseBodies of [true, false]) {
+      info("Test with decodeResponseBodies=" + decodeResponseBodies);
+      const events = [];
+      const noLimitNetworkObserver = createNetworkObserver({
+        events,
+        responseBodyLimit: 0,
+        decodeResponseBodies,
+      });
+
+      await performGetDataRequest(gBrowser, events, smallSize, useGzip);
+      await assertNetworkEventContent(events.at(-1), smallSize, false);
+
+      await performGetDataRequest(gBrowser, events, bigSize, useGzip);
+      await assertNetworkEventContent(events.at(-1), bigSize, false);
+
+      await performGetDataRequest(gBrowser, events, hugeSize, useGzip);
+      await assertNetworkEventContent(events.at(-1), hugeSize, false);
+
+      await performGetDataRequest(
+        gBrowser,
+        events,
+        tooManyArgumentsSize,
+        useGzip
+      );
+      await assertNetworkEventContent(
+        events.at(-1),
+        tooManyArgumentsSize,
+        false
+      );
+
+      noLimitNetworkObserver.destroy();
+    }
+  }
 
   gBrowser.removeTab(tab);
 });