From ea6b96ccdc2b54eea1486e0b37205717cc1f097f Mon Sep 17 00:00:00 2001
From: Joone Hur <joonehur@microsoft.com>
Date: Mon, 28 Sep 2026 18:34:05 -0700
Subject: [PATCH] Redact opaque script positions in LoAF promise attribution

Redact character, line, and column positions when capturing source
locations for opaque scripts.

Requires a companion V8 change providing StackFrame::IsScriptOpaque():
https://chromium-review.googlesource.com/c/v8/v8/+/8422987

Bug: 562158081, 502251640
Change-Id: Ic64040f8663b26c6ace883cc47a1e405a94e5ef4
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/8421802
Reviewed-by: Michal Mocny <mmocny@chromium.org>
Reviewed-by: Noam Rosenthal <nrosenthal@google.com>
Commit-Queue: Joone Hur <joonehur@microsoft.com>
Cr-Commit-Position: refs/heads/main@{#1706573}
---
diff --git a/third_party/blink/renderer/core/frame/animation_frame_timing_monitor.cc b/third_party/blink/renderer/core/frame/animation_frame_timing_monitor.cc
index 43066f8..9fbdeb2 100644
--- a/third_party/blink/renderer/core/frame/animation_frame_timing_monitor.cc
+++ b/third_party/blink/renderer/core/frame/animation_frame_timing_monitor.cc
@@ -944,14 +944,9 @@
       .class_like_name = class_like_name,
       .property_like_name = property_like_name,
       .source_location = {.url = location->Url(script_state->GetIsolate()),
-                          .char_position = location->CharPosition()}};
-
-  if (RuntimeEnabledFeatures::LongAnimationFrameSourceLineColumnEnabled()) {
-    pending_script_info_->source_location.line_number =
-        location->LineNumber() + 1;
-    pending_script_info_->source_location.column_number =
-        location->ColumnNumber() + 1;
-  }
+                          .char_position = location->CharPosition(),
+                          .line_number = location->LineNumber(),
+                          .column_number = location->ColumnNumber()}};
 }
 
 void AnimationFrameTimingMonitor::Will(
diff --git a/third_party/blink/renderer/platform/bindings/lazy_source_location.cc b/third_party/blink/renderer/platform/bindings/lazy_source_location.cc
index 4f4212f..e17d6c1 100644
--- a/third_party/blink/renderer/platform/bindings/lazy_source_location.cc
+++ b/third_party/blink/renderer/platform/bindings/lazy_source_location.cc
@@ -26,10 +26,16 @@
   }
 
   v8::Local<v8::StackFrame> stack_frame = stack_trace->GetFrame(isolate, 0);
-  int script_position = stack_frame->GetSourcePosition();
   v8::Local<v8::String> script_name_v8 =
       stack_frame->GetScriptNameOrSourceURL();
 
+  if (stack_frame->IsScriptOpaque()) {
+    return MakeGarbageCollected<LazySourceLocation>(isolate, script_name_v8,
+                                                    /*char_position=*/-1);
+  }
+
+  int script_position = stack_frame->GetSourcePosition();
+
   if (RuntimeEnabledFeatures::LongAnimationFrameSourceLineColumnEnabled()) {
     v8::Location location = stack_frame->GetLocation();
     return MakeGarbageCollected<LazySourceLocation>(
diff --git a/third_party/blink/renderer/platform/bindings/lazy_source_location.h b/third_party/blink/renderer/platform/bindings/lazy_source_location.h
index 729118e2..f0625a1 100644
--- a/third_party/blink/renderer/platform/bindings/lazy_source_location.h
+++ b/third_party/blink/renderer/platform/bindings/lazy_source_location.h
@@ -41,16 +41,18 @@
   static LazySourceLocation* FromCurrentStack(v8::Isolate* isolate);
   const String& Url(v8::Isolate* isolate);
   int CharPosition() const { return char_position_; }
-  int LineNumber() const { return line_number_; }
-  int ColumnNumber() const { return column_number_; }
+  int LineNumber() const { return line_number_ < 0 ? -1 : line_number_ + 1; }
+  int ColumnNumber() const {
+    return column_number_ < 0 ? -1 : column_number_ + 1;
+  }
   void Trace(Visitor* visitor) const;
 
  private:
   TraceWrapperV8Reference<v8::String> v8_url_;
   String url_;
   int char_position_ = -1;
-  int line_number_ = 0;
-  int column_number_ = 0;
+  int line_number_ = -1;
+  int column_number_ = -1;
 };
 
 }  // namespace blink
diff --git a/third_party/blink/web_tests/external/wpt/long-animation-frame/loaf-source-location-redirect.html b/third_party/blink/web_tests/external/wpt/long-animation-frame/loaf-source-location-redirect.html
index c1a631de..2459a69 100644
--- a/third_party/blink/web_tests/external/wpt/long-animation-frame/loaf-source-location-redirect.html
+++ b/third_party/blink/web_tests/external/wpt/long-animation-frame/loaf-source-location-redirect.html
@@ -63,7 +63,11 @@
         assert_not_equals(result, "empty", "CORS-ok scripts should expose sourceLocation");
       } else {
         assert_equals(result, "pre-redirect", "No-CORS classic scripts should expose pre-redirect URL");
-        assert_equals(script.sourceCharPosition, type === "script-block" || type === "resolve-promise" ? 0 : -1, "No-CORS classic scripts should not expose character index");
+        assert_equals(script.sourceCharPosition, type === "script-block" ? 0 : -1, "No-CORS scripts should not expose character indices");
+      }
+      if (type === "resolve-promise") {
+        assert_equals(script.sourceLine, cors ? 1 : -1, "Promise source line should be one-based or redacted");
+        assert_equals(script.sourceColumn, cors ? 1 : -1, "Promise source column should be one-based or redacted");
       }
     }, `Test ${type} with ${scriptType}`);
   }

diff --git a/third_party/blink/web_tests/external/wpt/long-animation-frame/loaf-source-location-redirect.html b/third_party/blink/web_tests/external/wpt/long-animation-frame/loaf-source-location-redirect.html
index c1a631de..2459a69 100644
--- a/third_party/blink/web_tests/external/wpt/long-animation-frame/loaf-source-location-redirect.html
+++ b/third_party/blink/web_tests/external/wpt/long-animation-frame/loaf-source-location-redirect.html
@@ -63,7 +63,11 @@
         assert_not_equals(result, "empty", "CORS-ok scripts should expose sourceLocation");
       } else {
         assert_equals(result, "pre-redirect", "No-CORS classic scripts should expose pre-redirect URL");
-        assert_equals(script.sourceCharPosition, type === "script-block" || type === "resolve-promise" ? 0 : -1, "No-CORS classic scripts should not expose character index");
+        assert_equals(script.sourceCharPosition, type === "script-block" ? 0 : -1, "No-CORS scripts should not expose character indices");
+      }
+      if (type === "resolve-promise") {
+        assert_equals(script.sourceLine, cors ? 1 : -1, "Promise source line should be one-based or redacted");
+        assert_equals(script.sourceColumn, cors ? 1 : -1, "Promise source column should be one-based or redacted");
       }
     }, `Test ${type} with ${scriptType}`);
   }