From 3373eb28a24608f9ae5d211c95c45e868a3d3758 Mon Sep 17 00:00:00 2001
From: Geoff Lang <geofflang@chromium.org>
Date: Tue, 19 May 2026 16:08:55 -0400
Subject: [PATCH] GL: Sync program state after transform feedback.

If we are syncing a call to BeginTransformFeedback,
PauseTransformFeedback, UseProgram all at once, the program will be
bound and then changed to an incorrect program when the transform
feedback active state is synced afterwards.

Fixed: chromium:513919827
Change-Id: I66562446d364d03f628f927b4f4e8f5d7113fe4b
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/7858018
Reviewed-by: Shahbaz Youssefi <syoussefi@chromium.org>
Commit-Queue: Shahbaz Youssefi <syoussefi@chromium.org>
---

diff --git a/src/libANGLE/renderer/gl/StateManagerGL.cpp b/src/libANGLE/renderer/gl/StateManagerGL.cpp
index 0d2bf2a..c48ce9f 100644
--- a/src/libANGLE/renderer/gl/StateManagerGL.cpp
+++ b/src/libANGLE/renderer/gl/StateManagerGL.cpp
@@ -2323,14 +2323,8 @@
                 updateDispatchIndirectBufferBinding(context);
                 break;
             case gl::state::DIRTY_BIT_PROGRAM_BINDING:
-            {
-                gl::Program *program = state.getProgram();
-                if (program != nullptr)
-                {
-                    useProgram(GetImplAs<ProgramGL>(program)->getProgramID());
-                }
+                syncProgramState(context);
                 break;
-            }
             case gl::state::DIRTY_BIT_PROGRAM_EXECUTABLE:
             {
                 const gl::ProgramExecutable *executable = state.getProgramExecutable();
@@ -2903,6 +2897,18 @@
         bindTransformFeedback(GL_TRANSFORM_FEEDBACK, 0);
         mCurrentTransformFeedback = nullptr;
     }
+
+    syncProgramState(context);
+}
+
+void StateManagerGL::syncProgramState(const gl::Context *context)
+{
+    gl::Program *program = context->getState().getProgram();
+    if (program != nullptr)
+    {
+        ProgramGL *programGL = GetImplAs<ProgramGL>(program);
+        useProgram(programGL->getProgramID());
+    }
 }
 
 GLuint StateManagerGL::getDefaultVAO() const
diff --git a/src/libANGLE/renderer/gl/StateManagerGL.h b/src/libANGLE/renderer/gl/StateManagerGL.h
index 795a690..b81ef6b 100644
--- a/src/libANGLE/renderer/gl/StateManagerGL.h
+++ b/src/libANGLE/renderer/gl/StateManagerGL.h
@@ -375,6 +375,7 @@
 
     void syncSamplersState(const gl::Context *context);
     void syncTransformFeedbackState(const gl::Context *context);
+    void syncProgramState(const gl::Context *context);
 
     void updateEmulatedClipDistanceState(const gl::ProgramExecutable *executable,
                                          const gl::ClipDistanceEnableBits enables) const;
diff --git a/src/libANGLE/renderer/gl/TransformFeedbackGL.cpp b/src/libANGLE/renderer/gl/TransformFeedbackGL.cpp
index 4caf28b..77b028b 100644
--- a/src/libANGLE/renderer/gl/TransformFeedbackGL.cpp
+++ b/src/libANGLE/renderer/gl/TransformFeedbackGL.cpp
@@ -162,10 +162,16 @@
         mStateManager->bindTransformFeedback(GL_TRANSFORM_FEEDBACK, mTransformFeedbackID);
         if (mIsPaused)
         {
+            // If we're transitioning from active to paused, the currently bound program must be the
+            // one associated with this transform feedback.
+            ASSERT(mStateManager->getProgramID() == mActiveProgram);
             mFunctions->pauseTransformFeedback();
         }
         else
         {
+            // When transitioning to resumed, make sure the program associated with this transform
+            // feedback is set
+            mStateManager->useProgram(mActiveProgram);
             mFunctions->resumeTransformFeedback();
         }
     }
diff --git a/src/tests/gl_tests/TransformFeedbackTest.cpp b/src/tests/gl_tests/TransformFeedbackTest.cpp
index 0e368c5..0ab7588 100644
--- a/src/tests/gl_tests/TransformFeedbackTest.cpp
+++ b/src/tests/gl_tests/TransformFeedbackTest.cpp
@@ -251,6 +251,34 @@
     EXPECT_EQ(primitivesWritten, 0u);
 }
 
+// Test that starting transform feedback with one program but pausing and drawing with another
+// program draws the expected results
+TEST_P(TransformFeedbackTest, DrawWithOtherProgramDuringPause)
+{
+    ANGLE_GL_PROGRAM(blueProgram, essl3_shaders::vs::Simple(), essl3_shaders::fs::Blue());
+
+    std::vector<std::string> tfVaryings;
+    tfVaryings.push_back("gl_Position");
+    compileDefaultProgram(tfVaryings, GL_INTERLEAVED_ATTRIBS);
+    glUseProgram(mProgram);
+
+    // Bind the buffer for transform feedback output and start transform feedback
+    glBindBufferBase(GL_TRANSFORM_FEEDBACK_BUFFER, 0, mTransformFeedbackBuffer);
+    glBeginTransformFeedback(GL_TRIANGLES);
+    glPauseTransformFeedback();
+    EXPECT_GL_NO_ERROR();
+
+    glUseProgram(blueProgram);
+    drawQuad(blueProgram, essl3_shaders::PositionAttrib(), 0.5f);
+    EXPECT_GL_NO_ERROR();
+
+    glUseProgram(mProgram);
+    glResumeTransformFeedback();
+    glEndTransformFeedback();
+
+    EXPECT_PIXEL_COLOR_EQ(0, 0, GLColor::blue);
+}
+
 // Test that resuming transform feedback with a different program results in validation error.
 TEST_P(TransformFeedbackTest, ProgramSwitchDuringPauseAndResume)
 {

diff --git a/src/tests/gl_tests/TransformFeedbackTest.cpp b/src/tests/gl_tests/TransformFeedbackTest.cpp
index 0e368c5..0ab7588 100644
--- a/src/tests/gl_tests/TransformFeedbackTest.cpp
+++ b/src/tests/gl_tests/TransformFeedbackTest.cpp
@@ -251,6 +251,34 @@
     EXPECT_EQ(primitivesWritten, 0u);
 }
 
+// Test that starting transform feedback with one program but pausing and drawing with another
+// program draws the expected results
+TEST_P(TransformFeedbackTest, DrawWithOtherProgramDuringPause)
+{
+    ANGLE_GL_PROGRAM(blueProgram, essl3_shaders::vs::Simple(), essl3_shaders::fs::Blue());
+
+    std::vector<std::string> tfVaryings;
+    tfVaryings.push_back("gl_Position");
+    compileDefaultProgram(tfVaryings, GL_INTERLEAVED_ATTRIBS);
+    glUseProgram(mProgram);
+
+    // Bind the buffer for transform feedback output and start transform feedback
+    glBindBufferBase(GL_TRANSFORM_FEEDBACK_BUFFER, 0, mTransformFeedbackBuffer);
+    glBeginTransformFeedback(GL_TRIANGLES);
+    glPauseTransformFeedback();
+    EXPECT_GL_NO_ERROR();
+
+    glUseProgram(blueProgram);
+    drawQuad(blueProgram, essl3_shaders::PositionAttrib(), 0.5f);
+    EXPECT_GL_NO_ERROR();
+
+    glUseProgram(mProgram);
+    glResumeTransformFeedback();
+    glEndTransformFeedback();
+
+    EXPECT_PIXEL_COLOR_EQ(0, 0, GLColor::blue);
+}
+
 // Test that resuming transform feedback with a different program results in validation error.
 TEST_P(TransformFeedbackTest, ProgramSwitchDuringPauseAndResume)
 {