From 29f339e26e11af5d56c5da1d6536bee0233d5194 Mon Sep 17 00:00:00 2001
From: John Preston <johnprestonmail@gmail.com>
Date: Fri, 3 Sep 2021 21:41:04 +0300
Subject: [PATCH] Allow Ui::GL::Renderer::deinit on lost context.

---
 ui/gl/gl_image.cpp   | 14 +++++++++-----
 ui/gl/gl_image.h     | 10 +++++-----
 ui/gl/gl_surface.cpp | 10 ++++++----
 ui/gl/gl_surface.h   |  2 +-
 4 files changed, 21 insertions(+), 15 deletions(-)

diff --git a/ui/gl/gl_image.cpp b/ui/gl/gl_image.cpp
index 3db6653..fc0e348 100644
--- a/ui/gl/gl_image.cpp
+++ b/ui/gl/gl_image.cpp
@@ -29,10 +29,12 @@ void GenerateTextures(
 	}
 }
 
-void DestroyTextures(QOpenGLFunctions &f, gsl::span<GLuint> values) {
+void DestroyTextures(QOpenGLFunctions *f, gsl::span<GLuint> values) {
 	Expects(!values.empty());
 
-	f.glDeleteTextures(values.size(), values.data());
+	if (f) {
+		f->glDeleteTextures(values.size(), values.data());
+	}
 	ranges::fill(values, 0);
 }
 
@@ -42,10 +44,12 @@ void GenerateFramebuffers(QOpenGLFunctions &f, gsl::span<GLuint> values) {
 	f.glGenFramebuffers(values.size(), values.data());
 }
 
-void DestroyFramebuffers(QOpenGLFunctions &f, gsl::span<GLuint> values) {
+void DestroyFramebuffers(QOpenGLFunctions *f, gsl::span<GLuint> values) {
 	Expects(!values.empty());
 
-	f.glDeleteTextures(values.size(), values.data());
+	if (f) {
+		f->glDeleteTextures(values.size(), values.data());
+	}
 	ranges::fill(values, 0);
 }
 
@@ -114,7 +118,7 @@ void Image::bind(QOpenGLFunctions &f) {
 	}
 }
 
-void Image::destroy(QOpenGLFunctions &f) {
+void Image::destroy(QOpenGLFunctions *f) {
 	_textures.destroy(f);
 	_cacheKey = 0;
 }
diff --git a/ui/gl/gl_image.h b/ui/gl/gl_image.h
index 75c24ec..736aa4d 100644
--- a/ui/gl/gl_image.h
+++ b/ui/gl/gl_image.h
@@ -18,10 +18,10 @@ void GenerateTextures(
 	gsl::span<GLuint> values,
 	GLint filter,
 	GLint clamp);
-void DestroyTextures(QOpenGLFunctions &f, gsl::span<GLuint> values);
+void DestroyTextures(QOpenGLFunctions *f, gsl::span<GLuint> values);
 
 void GenerateFramebuffers(QOpenGLFunctions &f, gsl::span<GLuint> values);
-void DestroyFramebuffers(QOpenGLFunctions &f, gsl::span<GLuint> values);
+void DestroyFramebuffers(QOpenGLFunctions *f, gsl::span<GLuint> values);
 
 } // namespace details
 
@@ -42,7 +42,7 @@ public:
 				clamp);
 		}
 	}
-	void destroy(QOpenGLFunctions &f) {
+	void destroy(QOpenGLFunctions *f) {
 		if (created()) {
 			details::DestroyTextures(f, gsl::make_span(_values));
 		}
@@ -79,7 +79,7 @@ public:
 			details::GenerateFramebuffers(f, gsl::make_span(_values));
 		}
 	}
-	void destroy(QOpenGLFunctions &f) {
+	void destroy(QOpenGLFunctions *f) {
 		if (created()) {
 			details::DestroyFramebuffers(f, gsl::make_span(_values));
 		}
@@ -113,7 +113,7 @@ public:
 	void invalidate();
 
 	void bind(QOpenGLFunctions &f);
-	void destroy(QOpenGLFunctions &f);
+	void destroy(QOpenGLFunctions *f);
 
 	[[nodiscard]] TexturedRect texturedRect(
 		const QRect &geometry,
diff --git a/ui/gl/gl_surface.cpp b/ui/gl/gl_surface.cpp
index 150210a..a08ffe6 100644
--- a/ui/gl/gl_surface.cpp
+++ b/ui/gl/gl_surface.cpp
@@ -107,11 +107,13 @@ void SurfaceOpenGL::callDeInit() {
 		return;
 	}
 	QObject::disconnect(base::take(_connection));
-	const auto surface = window()->windowHandle();
-	Assert(surface != nullptr);
+	makeCurrent();
 	const auto context = this->context();
-	context->makeCurrent(surface);
-	_renderer->deinit(this, *context->functions());
+	_renderer->deinit(
+		this,
+		((isValid() && context && QOpenGLContext::currentContext() == context)
+			? context->functions()
+			: nullptr));
 }
 
 SurfaceRaster::SurfaceRaster(
diff --git a/ui/gl/gl_surface.h b/ui/gl/gl_surface.h
index 1bf5981..2877816 100644
--- a/ui/gl/gl_surface.h
+++ b/ui/gl/gl_surface.h
@@ -28,7 +28,7 @@ public:
 
     virtual void deinit(
         not_null<QOpenGLWidget*> widget,
-        QOpenGLFunctions &f) {
+        QOpenGLFunctions *f) {
     }
 
     virtual void resize(