1 files changed, 39 insertions, 0 deletions
diff --git a/src/tests/gl_tests/GLSLTest.cpp b/src/tests/gl_tests/GLSLTest.cpp
index 7b6e70d168..b34db39c4a 100644
--- a/src/tests/gl_tests/GLSLTest.cpp
+++ b/src/tests/gl_tests/GLSLTest.cpp
@@ -9094,6 +9094,45 @@ void main()
     EXPECT_NE(compileResult, 0);
 }
 
+// Test that packing of excessive 3-column variables does not overflow the count of 3-column
+// variables in VariablePacker
+TEST_P(WebGL2GLSLTest, ExcessiveMat3UniformPacking)
+{
+    std::ostringstream srcStream;
+
+    srcStream << "#version 300 es\n";
+    srcStream << "precision mediump float;\n";
+    srcStream << "out vec4 finalColor;\n";
+    srcStream << "in vec4 color;\n";
+    srcStream << "uniform mat4 r[254];\n";
+
+    srcStream << "uniform mat3 ";
+    constexpr size_t kNumUniforms = 10000;
+    for (size_t i = 0; i < kNumUniforms; ++i)
+    {
+        if (i > 0)
+        {
+            srcStream << ", ";
+        }
+        srcStream << "m3a_" << i << "[256]";
+    }
+    srcStream << ";\n";
+
+    srcStream << "void main(void) { finalColor = color; }\n";
+    std::string src = std::move(srcStream).str();
+
+    GLuint shader = glCreateShader(GL_VERTEX_SHADER);
+
+    const char *sourceArray[1] = {src.c_str()};
+    GLint lengths[1]           = {static_cast<GLint>(src.length())};
+    glShaderSource(shader, 1, sourceArray, lengths);
+    glCompileShader(shader);
+
+    GLint compileResult;
+    glGetShaderiv(shader, GL_COMPILE_STATUS, &compileResult);
+    EXPECT_EQ(compileResult, 0);
+}
+
 // Test that a varying with a flat qualifier that is used as an operand of a folded ternary operator
 // is handled correctly.
 TEST_P(GLSLTest_ES3, FlatVaryingUsedInFoldedTernary)