Disallow samplers as ternary operands

src/compiler/translator/ParseContext.cpp

@@ -4321,6 +4321,17 @@ TIntermTyped *TParseContext::addTernarySelection(TIntermTyped *cond,
                       falseExpression->getCompleteString());
         return falseExpression;
     }
+    if (IsOpaqueType(trueExpression->getBasicType()))
+    {
+        // ESSL 1.00 section 4.1.7
+        // ESSL 3.00 section 4.1.7
+        // Opaque/sampler types are not allowed in most types of expressions, including ternary.
+        // Note that structs containing opaque types don't need to be checked as structs are
+        // forbidden below.
+        error(loc, "ternary operator is not allowed for opaque types", ":");
+        return falseExpression;
+    }
+
     // ESSL1 sections 5.2 and 5.7:
     // ESSL3 section 5.7:
     // Ternary operator is not among the operators allowed for structures/arrays.

src/tests/compiler_tests/MalformedShader_test.cpp

@@ -2981,3 +2981,22 @@ TEST_F(MalformedFragmentShaderGLES31Test, ImageInternalFormatInGlobalLayoutQuali
         FAIL() << "Shader compilation succeeded, expecting failure " << mInfoLog;
     }
 }
+
+// ESSL 1.00 section 4.1.7.
+// Samplers are not allowed as operands for most operations. Test this for ternary operator.
+TEST_F(MalformedShaderTest, SamplerAsTernaryOperand)
+{
+    const std::string &shaderString =
+        "precision mediump float;\n"
+        "uniform bool u;\n"
+        "uniform sampler2D s1;\n"
+        "uniform sampler2D s2;\n"
+        "void main() {\n"
+        "    gl_FragColor = texture2D(u ? s1 : s2, vec2(0, 0));\n"
+        "}\n";
+
+    if (compile(shaderString))
+    {
+        FAIL() << "Shader compilation succeeded, expecting failure " << mInfoLog;
+    }
+}