From 6ada72e09d8b304036e07bfb67b72c7b1ced7a1a Mon Sep 17 00:00:00 2001
From: twinaphex <libretro@gmail.com>
Date: Mon, 29 Jun 2020 22:06:50 +0200
Subject: [PATCH] (gl_raster_font) Try to prevent NULL pointer dereferences

---
 gfx/drivers_font/gl_raster_font.c | 73 +++++++++++++++++--------------
 1 file changed, 40 insertions(+), 33 deletions(-)

diff --git a/gfx/drivers_font/gl_raster_font.c b/gfx/drivers_font/gl_raster_font.c
index 505e9b8ca6..84072e5bcf 100644
--- a/gfx/drivers_font/gl_raster_font.c
+++ b/gfx/drivers_font/gl_raster_font.c
@@ -90,9 +90,8 @@ static bool gl_raster_font_upload_atlas_components_4(gl_raster_t *font)
    GLint  gl_internal                   = GL_RGBA;
    GLenum gl_format                     = GL_RGBA;
    size_t ncomponents                   = 4;
-   uint8_t       *tmp                   = NULL;
-
-   tmp = (uint8_t*)calloc(font->tex_height, font->tex_width * ncomponents);
+   uint8_t       *tmp                   = (uint8_t*)
+      calloc(font->tex_height, font->tex_width * ncomponents);
 
    for (i = 0; i < font->atlas->height; ++i)
    {
@@ -109,7 +108,8 @@ static bool gl_raster_font_upload_atlas_components_4(gl_raster_t *font)
       break;
    }
 
-   glTexImage2D(GL_TEXTURE_2D, 0, gl_internal, font->tex_width, font->tex_height,
+   glTexImage2D(GL_TEXTURE_2D, 0, gl_internal,
+         font->tex_width, font->tex_height,
          0, gl_format, GL_UNSIGNED_BYTE, tmp);
 
    free(tmp);
@@ -128,9 +128,9 @@ static bool gl_raster_font_upload_atlas(gl_raster_t *font)
 #if defined(GL_VERSION_3_0)
    struct retro_hw_render_callback *hwr = video_driver_get_hw_context();
 
-    if (font->gl->core_context_in_use ||
-        (hwr->context_type == RETRO_HW_CONTEXT_OPENGL &&
-         hwr->version_major >= 3))
+   if ((font->gl && font->gl->core_context_in_use) ||
+         (hwr->context_type == RETRO_HW_CONTEXT_OPENGL &&
+          hwr->version_major >= 3))
    {
       GLint swizzle[] = { GL_ONE, GL_ONE, GL_ONE, GL_RED };
       glTexParameteriv(GL_TEXTURE_2D, GL_TEXTURE_SWIZZLE_RGBA, swizzle);
@@ -169,7 +169,8 @@ static bool gl_raster_font_upload_atlas(gl_raster_t *font)
          break;
    }
 
-   glTexImage2D(GL_TEXTURE_2D, 0, gl_internal, font->tex_width, font->tex_height,
+   glTexImage2D(GL_TEXTURE_2D, 0, gl_internal,
+         font->tex_width, font->tex_height,
          0, gl_format, GL_UNSIGNED_BYTE, tmp);
 
    free(tmp);
@@ -217,7 +218,8 @@ static void *gl_raster_font_init_font(void *data,
 
    font->atlas->dirty = false;
 
-   glBindTexture(GL_TEXTURE_2D, font->gl->texture[font->gl->tex_index]);
+   if (font->gl)
+      glBindTexture(GL_TEXTURE_2D, font->gl->texture[font->gl->tex_index]);
 
    return font;
 
@@ -267,9 +269,12 @@ static void gl_raster_font_draw_vertices(gl_raster_t *font,
       font->atlas->dirty   = false;
    }
 
-   font->gl->shader->set_coords(font->gl->shader_data, coords);
-   font->gl->shader->set_mvp(font->gl->shader_data,
-         &font->gl->mvp_no_rot);
+   if (font->gl && font->gl->shader)
+   {
+      font->gl->shader->set_coords(font->gl->shader_data, coords);
+      font->gl->shader->set_mvp(font->gl->shader_data,
+            &font->gl->mvp_no_rot);
+   }
 
    glDrawArrays(GL_TRIANGLES, 0, coords->vertices);
 }
@@ -407,7 +412,7 @@ static void gl_raster_font_setup_viewport(unsigned width, unsigned height,
 
    glBindTexture(GL_TEXTURE_2D, font->tex);
 
-   if (font->gl->shader && font->gl->shader->use)
+   if (font->gl && font->gl->shader && font->gl->shader->use)
       font->gl->shader->use(font->gl,
             font->gl->shader_data, VIDEO_SHADER_STOCK_BLEND, true);
 }
@@ -481,36 +486,38 @@ static void gl_raster_font_render_msg(
    else
       gl_raster_font_setup_viewport(width, height, font, full_screen);
 
-   if (!string_is_empty(msg) && font->gl
-         && font->font_data  && font->font_driver)
+   if (font->gl)
    {
-      if (drop_x || drop_y)
+      if (    !string_is_empty(msg)
+            && font->font_data  
+            && font->font_driver)
       {
-         GLfloat color_dark[4];
+         if (drop_x || drop_y)
+         {
+            GLfloat color_dark[4];
 
-         color_dark[0] = color[0] * drop_mod;
-         color_dark[1] = color[1] * drop_mod;
-         color_dark[2] = color[2] * drop_mod;
-         color_dark[3] = color[3] * drop_alpha;
+            color_dark[0] = color[0] * drop_mod;
+            color_dark[1] = color[1] * drop_mod;
+            color_dark[2] = color[2] * drop_mod;
+            color_dark[3] = color[3] * drop_alpha;
 
-         if (font->gl)
             gl_raster_font_render_message(font, msg, scale, color_dark,
                   x + scale * drop_x / font->gl->vp.width, y +
-                  scale * drop_y / font->gl->vp.height, text_align);
-      }
+                      scale * drop_y / font->gl->vp.height, text_align);
+         }
 
-      if (font->gl)
          gl_raster_font_render_message(font, msg, scale, color,
                x, y, text_align);
-   }
+      }
 
-   if (!font->block && font->gl)
-   {
-      /* restore viewport */
-      glBindTexture(GL_TEXTURE_2D, font->gl->texture[font->gl->tex_index]);
-
-      glDisable(GL_BLEND);
-      video_driver_set_viewport(width, height, false, true);
+      if (!font->block)
+      {
+         /* restore viewport */
+         glBindTexture(GL_TEXTURE_2D,
+               font->gl->texture[font->gl->tex_index]);
+         glDisable(GL_BLEND);
+         video_driver_set_viewport(width, height, false, true);
+      }
    }
 }