diff --git a/executor/xeXMLWriter.cpp b/executor/xeXMLWriter.cpp
index 387c8c9..feaa2c9 100644
--- a/executor/xeXMLWriter.cpp
+++ b/executor/xeXMLWriter.cpp
@@ -41,6 +41,38 @@
 		case '&':	return "&amp;";
 		case '\'':	return "&apos;";
 		case '"':	return "&quot;";
+
+		// Non-printable characters.
+		case 0:		return "&lt;NUL&gt;";
+		case 1:		return "&lt;SOH&gt;";
+		case 2:		return "&lt;STX&gt;";
+		case 3:		return "&lt;ETX&gt;";
+		case 4:		return "&lt;EOT&gt;";
+		case 5:		return "&lt;ENQ&gt;";
+		case 6:		return "&lt;ACK&gt;";
+		case 7:		return "&lt;BEL&gt;";
+		case 8:		return "&lt;BS&gt;";
+		case 11:	return "&lt;VT&gt;";
+		case 12:	return "&lt;FF&gt;";
+		case 14:	return "&lt;SO&gt;";
+		case 15:	return "&lt;SI&gt;";
+		case 16:	return "&lt;DLE&gt;";
+		case 17:	return "&lt;DC1&gt;";
+		case 18:	return "&lt;DC2&gt;";
+		case 19:	return "&lt;DC3&gt;";
+		case 20:	return "&lt;DC4&gt;";
+		case 21:	return "&lt;NAK&gt;";
+		case 22:	return "&lt;SYN&gt;";
+		case 23:	return "&lt;ETB&gt;";
+		case 24:	return "&lt;CAN&gt;";
+		case 25:	return "&lt;EM&gt;";
+		case 26:	return "&lt;SUB&gt;";
+		case 27:	return "&lt;ESC&gt;";
+		case 28:	return "&lt;FS&gt;";
+		case 29:	return "&lt;GS&gt;";
+		case 30:	return "&lt;RS&gt;";
+		case 31:	return "&lt;US&gt;";
+
 		default:	return DE_NULL;
 	}
 }
diff --git a/framework/opengl/gluShaderProgram.cpp b/framework/opengl/gluShaderProgram.cpp
index 3070bc8..7c273d8 100644
--- a/framework/opengl/gluShaderProgram.cpp
+++ b/framework/opengl/gluShaderProgram.cpp
@@ -89,23 +89,45 @@
 
 	GLU_EXPECT_NO_ERROR(m_gl.getError(), "glCompileShader()");
 
-	// Query status & log.
+	// Query status
 	{
-		int	compileStatus	= 0;
-		int	infoLogLen		= 0;
-		int	unusedLen;
+		int compileStatus = 0;
 
-		m_gl.getShaderiv(m_shader, GL_COMPILE_STATUS,		&compileStatus);
-		m_gl.getShaderiv(m_shader, GL_INFO_LOG_LENGTH,	&infoLogLen);
+		m_gl.getShaderiv(m_shader, GL_COMPILE_STATUS, &compileStatus);
 		GLU_EXPECT_NO_ERROR(m_gl.getError(), "glGetShaderiv()");
 
 		m_info.compileOk = compileStatus != GL_FALSE;
+	}
+
+	// Query log
+	{
+		int infoLogLen = 0;
+		int unusedLen;
+
+		m_gl.getShaderiv(m_shader, GL_INFO_LOG_LENGTH, &infoLogLen);
+		GLU_EXPECT_NO_ERROR(m_gl.getError(), "glGetShaderiv()");
 
 		if (infoLogLen > 0)
 		{
-			std::vector<char> infoLog(infoLogLen);
-			m_gl.getShaderInfoLog(m_shader, (int)infoLog.size(), &unusedLen, &infoLog[0]);
-			m_info.infoLog = std::string(&infoLog[0], infoLogLen);
+			// The INFO_LOG_LENGTH query and the buffer query implementations have
+			// very commonly off-by-one errors. Try to work around these issues.
+
+			// add tolerance for off-by-one in log length, buffer write, and for terminator
+			std::vector<char> infoLog(infoLogLen + 3, '\0');
+
+			// claim buf size is one smaller to protect from off-by-one writing over buffer bounds
+			m_gl.getShaderInfoLog(m_shader, (int)infoLog.size() - 1, &unusedLen, &infoLog[0]);
+
+			if (infoLog[(int)(infoLog.size()) - 1] != '\0')
+			{
+				// return whole buffer if null terminator was overwritten
+				m_info.infoLog = std::string(&infoLog[0], infoLog.size());
+			}
+			else
+			{
+				// read as C string. infoLog is guaranteed to be 0-terminated
+				m_info.infoLog = std::string(&infoLog[0]);
+			}
 		}
 	}
 }
diff --git a/modules/gles31/functional/es31fNegativeShaderApiTests.cpp b/modules/gles31/functional/es31fNegativeShaderApiTests.cpp
index e0d5a6e..a35b941 100644
--- a/modules/gles31/functional/es31fNegativeShaderApiTests.cpp
+++ b/modules/gles31/functional/es31fNegativeShaderApiTests.cpp
@@ -555,8 +555,8 @@
 
 void get_sampler_parameterfv (NegativeTestContext& ctx)
 {
-	float			params;
-	GLuint			sampler = 0;
+	float				params	= 0.0f;
+	GLuint				sampler = 0;
 	ctx.glGenSamplers	(1, &sampler);
 
 	ctx.beginSection("GL_INVALID_OPERATION is generated if sampler is not the name of a sampler object returned from a previous call to ctx.glGenSamplers.");
diff --git a/modules/gles31/functional/es31fNegativeStateApiTests.cpp b/modules/gles31/functional/es31fNegativeStateApiTests.cpp
index 53a42b9..8f07c11 100644
--- a/modules/gles31/functional/es31fNegativeStateApiTests.cpp
+++ b/modules/gles31/functional/es31fNegativeStateApiTests.cpp
@@ -335,10 +335,10 @@
 
 void get_program_info_log (NegativeTestContext& ctx)
 {
-	GLuint program	= ctx.glCreateProgram();
-	GLuint shader	= ctx.glCreateShader(GL_VERTEX_SHADER);
-	GLsizei length[1];
-	char infoLog[1];
+	GLuint	program		= ctx.glCreateProgram();
+	GLuint	shader		= ctx.glCreateShader(GL_VERTEX_SHADER);
+	GLsizei	length[1]	= { 0 };
+	char	infoLog[1]	= { 'x' };
 
 	ctx.beginSection("GL_INVALID_VALUE is generated if program is not a value generated by OpenGL.");
 	ctx.glGetProgramInfoLog (-1, 1, &length[0], &infoLog[0]);