Renderers: Make info log evaluation more robust. (#31438)

src/renderers/webgl-fallback/WebGLBackend.js

@@ -1574,7 +1574,9 @@ class WebGLBackend extends Backend {
 	_getShaderErrors( gl, shader, type ) {
 
 		const status = gl.getShaderParameter( shader, gl.COMPILE_STATUS );
-		const errors = gl.getShaderInfoLog( shader ).trim();
+
+		const shaderInfoLog = gl.getShaderInfoLog( shader ) || '';
+		const errors = shaderInfoLog.trim();
 
 		if ( status && errors === '' ) return '';
 
@@ -1606,11 +1608,11 @@ class WebGLBackend extends Backend {
 
 			const gl = this.gl;
 
-			const programLog = gl.getProgramInfoLog( programGPU ).trim();
+			const programInfoLog = gl.getProgramInfoLog( programGPU ) || '';
+			const programLog = programInfoLog.trim();
 
 			if ( gl.getProgramParameter( programGPU, gl.LINK_STATUS ) === false ) {
 
-
 				if ( typeof this.renderer.debug.onShaderError === 'function' ) {
 
 					this.renderer.debug.onShaderError( gl, programGPU, glVertexShader, glFragmentShader );

src/renderers/webgl/WebGLProgram.js

@@ -57,7 +57,9 @@ function getEncodingComponents( colorSpace ) {
 function getShaderErrors( gl, shader, type ) {
 
 	const status = gl.getShaderParameter( shader, gl.COMPILE_STATUS );
-	const errors = gl.getShaderInfoLog( shader ).trim();
+
+	const shaderInfoLog = gl.getShaderInfoLog( shader ) || '';
+	const errors = shaderInfoLog.trim();
 
 	if ( status && errors === '' ) return '';
 
@@ -918,9 +920,13 @@ function WebGLProgram( renderer, cacheKey, parameters, bindingStates ) {
 		// check for link errors
 		if ( renderer.debug.checkShaderErrors ) {
 
-			const programLog = gl.getProgramInfoLog( program ).trim();
-			const vertexLog = gl.getShaderInfoLog( glVertexShader ).trim();
-			const fragmentLog = gl.getShaderInfoLog( glFragmentShader ).trim();
+			const programInfoLog = gl.getProgramInfoLog( program ) || '';
+			const vertexShaderInfoLog = gl.getShaderInfoLog( glVertexShader ) || '';
+			const fragmentShaderInfoLog = gl.getShaderInfoLog( glFragmentShader ) || '';
+
+			const programLog = programInfoLog.trim();
+			const vertexLog = vertexShaderInfoLog.trim();
+			const fragmentLog = fragmentShaderInfoLog.trim();
 
 			let runnable = true;
 			let haveDiagnostics = true;