Fix shader info log including 0-terminator.

Change-Id: I6722327906f76a06634606daa740981ebdf8540a

diff --git a/framework/opengl/gluShaderProgram.cpp b/framework/opengl/gluShaderProgram.cpp
index 3070bc8..7c273d8 100644 (file)
--- a/framework/opengl/gluShaderProgram.cpp
+++ b/framework/opengl/gluShaderProgram.cpp
@@ -89,23 +89,45 @@ void Shader::compile (void)
 
        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]);
+                       }
                }
        }
 }