don't delete the shaders before the program

some GPU drivers have issues with deleting shader objects that are attached to programs. while this is allowed by the spec, it seems that some drivers are crashing nonetheless.

2 files changed, 9 insertions, 8 deletions

diff --git a/src/mbgl/shader/shader.cpp b/src/mbgl/shader/shader.cpp
index ed4cb729b3..c69518c8c8 100644
--- a/src/mbgl/shader/shader.cpp
+++ b/src/mbgl/shader/shader.cpp
@@ -20,8 +20,6 @@ Shader::Shader(const char *name_, const GLchar *vertSource, const GLchar *fragSo
 
     program = MBGL_CHECK_ERROR(glCreateProgram());
 
-    GLuint vertShader = 0;
-    GLuint fragShader = 0;
     if (!compileShader(&vertShader, GL_VERTEX_SHADER, vertSource)) {
         Log::Error(Event::Shader, "Vertex shader %s failed to compile: %s", name, vertSource);
         MBGL_CHECK_ERROR(glDeleteProgram(program));
@@ -67,12 +65,6 @@ Shader::Shader(const char *name_, const GLchar *vertSource, const GLchar *fragSo
         }
     }
 
-    // Remove the compiled shaders; they are now part of the program.
-    MBGL_CHECK_ERROR(glDetachShader(program, vertShader));
-    MBGL_CHECK_ERROR(glDeleteShader(vertShader));
-    MBGL_CHECK_ERROR(glDetachShader(program, fragShader));
-    MBGL_CHECK_ERROR(glDeleteShader(fragShader));
-
     a_pos = MBGL_CHECK_ERROR(glGetAttribLocation(program, "a_pos"));
 }
 
@@ -115,7 +107,13 @@ bool Shader::compileShader(GLuint *shader, GLenum type, const GLchar *source) {
 
 Shader::~Shader() {
     if (program) {
+        MBGL_CHECK_ERROR(glDetachShader(program, vertShader));
+        MBGL_CHECK_ERROR(glDetachShader(program, fragShader));
         MBGL_CHECK_ERROR(glDeleteProgram(program));
         program = 0;
+        MBGL_CHECK_ERROR(glDeleteShader(vertShader));
+        vertShader = 0;
+        MBGL_CHECK_ERROR(glDeleteShader(fragShader));
+        fragShader = 0;
     }
 }
diff --git a/src/mbgl/shader/shader.hpp b/src/mbgl/shader/shader.hpp
index 9b150c37ed..3290224796 100644
--- a/src/mbgl/shader/shader.hpp
+++ b/src/mbgl/shader/shader.hpp
@@ -28,6 +28,9 @@ protected:
 
 private:
     bool compileShader(uint32_t *shader, uint32_t type, const char *source);
+
+    uint32_t vertShader = 0;
+    uint32_t fragShader = 0;
 };
 
 }