Fix crash in release_texture() called in frame destructor.

The "close glsl" event handler would destroy the texture container
objects while lingering frames still held references to them.

diff --git a/src/modules/opengl/filter_glsl_manager.cpp b/src/modules/opengl/filter_glsl_manager.cpp
index 28bd13fb675320addb458ad7dddce4c5019a46b9..f1dfaa6a469f4183185381d587f50aedca92ae14 100644 (file)
--- a/src/modules/opengl/filter_glsl_manager.cpp
+++ b/src/modules/opengl/filter_glsl_manager.cpp
@@ -70,6 +70,10 @@ GlslManager::~GlslManager()
 {
        mlt_log_debug(get_service(), "%s\n", __FUNCTION__);
        cleanupContext();
+// XXX If there is still a frame holding a reference to a texture after this
+// destructor is called, then it will crash in release_texture().
+//     while (texture_list.peek_back())
+//             delete (glsl_texture) texture_list.pop_back();
        delete initEvent;
        delete closeEvent;
 }
@@ -141,18 +145,31 @@ glsl_texture GlslManager::get_texture(int width, int height, GLint internal_form
                        return tex;
                }
        }
+
+       // Recycle a glsl_texture with deleted glTexture.
+       glsl_texture gtex = 0;
+       for (int i = 0; i < texture_list.count(); ++i) {
+               glsl_texture tex = (glsl_texture) texture_list.peek(i);
+               if (!tex->used && !tex->width && !tex->height) {
+                       gtex = tex;
+                       break;
+               }
+       }
        unlock();
 
        GLuint tex = 0;
        glGenTextures(1, &tex);
-       if (!tex)
+       if (!tex) {
+               glDeleteTextures(1, &tex);
                return NULL;
+       }
 
-       glsl_texture gtex = new glsl_texture_s;
        if (!gtex) {
-               glDeleteTextures(1, &tex);
-               return NULL;
+               gtex = new glsl_texture_s;
+               if (!gtex)
+                       return NULL;
        }
+
        glBindTexture( GL_TEXTURE_2D, tex );
        glTexImage2D( GL_TEXTURE_2D, 0, internal_format, width, height, 0, internal_format, GL_UNSIGNED_BYTE, NULL );
     glTexParameterf( GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE );
@@ -215,10 +232,12 @@ void GlslManager::cleanupContext()
                glDeleteFramebuffers(1, &fbo->fbo);
                delete fbo;
        }
-       while (texture_list.peek_back()) {
-               glsl_texture texture = (glsl_texture) texture_list.pop_back();
+       for (int i = 0; i < texture_list.count(); ++i) {
+               glsl_texture texture = (glsl_texture) texture_list.peek(i);
                glDeleteTextures(1, &texture->texture);
-               delete texture;
+               texture->used = 0;
+               texture->width = 0;
+               texture->height = 0;
        }
        if (pbo) {
                glDeleteBuffers(1, &pbo->pbo);