Safe pipeline gui functions (shutdown part 3)

If we process the pixelpipe after dt_control_quit() the gui is not available any more and thus also the references
to it in the pipe's dev.

The relevant functions are
1. the checking for module being in focus, instead of adding an additional check all over the code dt_iop_has_focus()
   has been introduced and used all over the code where correct.
2. dt_dev_gui_module(void) also tests for a gui being available

Author: jenshannoschwalm

src/develop/blend.c

@@ -504,9 +504,7 @@ void dt_develop_blend_process(dt_iop_module_t *self,
                               const dt_iop_roi_t *const roi_in,
                               const dt_iop_roi_t *const roi_out)
 {
-  if(piece->pipe->bypass_blendif
-     && self->dev->gui_attached
-     && (self == self->dev->gui_module))
+  if(piece->pipe->bypass_blendif && dt_iop_has_focus(self))
     return;
 
   const dt_develop_blend_params_t *const d = piece->blendop_data;
@@ -545,10 +543,7 @@ void dt_develop_blend_process(dt_iop_module_t *self,
     return;
   }
 
-  const gboolean valid_request =
-      self->dev->gui_attached
-      && (self == self->dev->gui_module)
-      && (piece->pipe == self->dev->full.pipe);
+  const gboolean valid_request = dt_iop_has_focus(self) && (piece->pipe == self->dev->full.pipe);
 
   // does user want us to display a specific channel?
   const dt_dev_pixelpipe_display_mask_t request_mask_display =
@@ -934,9 +929,7 @@ gboolean dt_develop_blend_process_cl(dt_iop_module_t *self,
                                      const dt_iop_roi_t *roi_in,
                                      const dt_iop_roi_t *roi_out)
 {
-  if(piece->pipe->bypass_blendif
-      && self->dev->gui_attached
-      && (self == self->dev->gui_module))
+  if(piece->pipe->bypass_blendif && dt_iop_has_focus(self))
     return TRUE;
 
   dt_develop_blend_params_t *const d = piece->blendop_data;
@@ -971,10 +964,7 @@ gboolean dt_develop_blend_process_cl(dt_iop_module_t *self,
   // only non-zero if mask_display was set by an _earlier_ module
   const dt_dev_pixelpipe_display_mask_t mask_display = piece->pipe->mask_display;
 
-  const gboolean valid_request =
-      self->dev->gui_attached
-      && (self == self->dev->gui_module)
-      && (piece->pipe == self->dev->full.pipe);
+  const gboolean valid_request = dt_iop_has_focus(self) && (piece->pipe == self->dev->full.pipe);
 
   // does user want us to display a specific channel?
   const dt_dev_pixelpipe_display_mask_t request_mask_display =

src/develop/develop.h

@@ -616,7 +616,7 @@ void dt_dev_init_chroma(dt_develop_t *dev);
 void dt_dev_clear_chroma_troubles(dt_develop_t *dev);
 static inline struct dt_iop_module_t *dt_dev_gui_module(void)
 {
-  return darktable.develop ? darktable.develop->gui_module : NULL;
+  return (darktable.develop && darktable.gui) ? darktable.develop->gui_module : NULL;
 }
 
 #ifdef __cplusplus

src/develop/imageop.c

@@ -2310,6 +2310,17 @@ static gboolean _presets_scroll_callback(GtkWidget *widget,
   return TRUE;
 }
 
+// Make sure we don't dereference if not in UI mode any more
+gboolean dt_iop_has_focus(dt_iop_module_t *module)
+{
+  return module
+      && module->dev
+      && module->dev->gui_attached
+      && module == module->dev->gui_module
+      && darktable.gui
+      && dt_dev_modulegroups_test_activated(darktable.develop);
+}
+
 void dt_iop_request_focus(dt_iop_module_t *module)
 {
   dt_develop_t *dev = darktable.develop;
@@ -2320,7 +2331,8 @@ void dt_iop_request_focus(dt_iop_module_t *module)
   if(!darktable.lib->proxy.colorpicker.restrict_histogram)
     dt_iop_color_picker_reset(NULL, TRUE);
 
-  if(darktable.gui->reset
+  if(!darktable.gui
+     || darktable.gui->reset
      || (out_focus_module == module))
     return;
 

src/develop/imageop.h

@@ -412,6 +412,8 @@ GtkWidget *dt_iop_gui_header_button(dt_iop_module_t *module,
 
 /** requests the focus for this plugin (to draw overlays over the center image) */
 void dt_iop_request_focus(dt_iop_module_t *module);
+/** returns TRUE if tested module has focus */
+gboolean dt_iop_has_focus(dt_iop_module_t *module);
 /** allocate and load default settings from introspection. */
 void dt_iop_default_init(dt_iop_module_t *module);
 /** loads default settings from database. */

src/iop/ashift.c

@@ -4054,13 +4054,6 @@ static gboolean _get_points(dt_iop_module_t *self,
   return FALSE;
 }
 
-// does this gui have focus?
-static gboolean _gui_has_focus(dt_iop_module_t *self)
-{
-  return (self->dev->gui_module == self
-          && dt_dev_modulegroups_test_activated(darktable.develop));
-}
-
 /* this function replaces this sentence, it calls distort_transform()
    for this module on the pipe
    if(!dt_dev_distort_transform_plus(self->dev, self->dev->preview_pipe,
@@ -4154,7 +4147,7 @@ void gui_post_expose(dt_iop_module_t *self,
 
   // we draw the cropping area; we need x_off/y_off/width/height which is only available
   // after g->buf has been processed
-  if(g->buf && self->enabled && _gui_has_focus(self))
+  if(g->buf && self->enabled && dt_iop_has_focus(self))
   {
     // roi data of the preview pipe input buffer
 
@@ -4354,7 +4347,7 @@ void gui_post_expose(dt_iop_module_t *self,
   if(g->fitting) return;
 
   // no structural data or visibility switched off? -> stop here
-  if(g->lines == NULL || !_gui_has_focus(self)) return;
+  if(g->lines == NULL || !dt_iop_has_focus(self)) return;
 
   // get hash value that reflects distortions from here to the end of the pixelpipe
   const dt_hash_t hash = dt_dev_hash_distort_plus(dev,
@@ -5630,7 +5623,7 @@ void commit_params(dt_iop_module_t *self,
   d->orthocorr = (p->mode == ASHIFT_MODE_GENERIC) ? 0.0f : p->orthocorr;
   d->aspect = (p->mode == ASHIFT_MODE_GENERIC) ? 1.0f : p->aspect;
 
-  if(_gui_has_focus(self)
+  if(dt_iop_has_focus(self)
      || dt_isnan(p->cl)
      || dt_isnan(p->cr)
      || dt_isnan(p->ct)

src/iop/clipping.c

@@ -391,12 +391,6 @@ dt_iop_colorspace_type_t default_colorspace(dt_iop_module_t *self,
   return IOP_CS_RGB;
 }
 
-static int gui_has_focus(dt_iop_module_t *self)
-{
-  return (self->dev->gui_module == self
-          && dt_dev_modulegroups_test_activated(darktable.develop));
-}
-
 static void keystone_get_matrix(const dt_boundingbox_t k_space, float kxa, float kxb, float kxc, float kxd, float kya,
                                 float kyb, float kyc, float kyd, float *a, float *b, float *d, float *e,
                                 float *g, float *h)
@@ -1328,7 +1322,7 @@ void commit_params(dt_iop_module_t *self, dt_iop_params_t *p1, dt_dev_pixelpipe_
     d->k_apply = 0;
   }
 
-  if(gui_has_focus(self))
+  if(dt_iop_has_focus(self))
   {
     d->cx = 0.0f;
     d->cy = 0.0f;

src/iop/colorequal.c

@@ -2537,7 +2537,7 @@ static gboolean _iop_colorequalizer_draw(GtkWidget *widget,
 
   dt_free_align(g->LUT);
 
-  if(self->enabled && (self == self->dev->gui_module) && g->picking)
+  if(self->enabled && dt_iop_has_focus(self) && g->picking)
     _draw_color_picker(self, cr, p, g, (double)graph_width, (double)graph_height);
 
   cairo_restore(cr);

src/iop/colorzones.c

@@ -585,8 +585,9 @@ void process(dt_iop_module_t *self,
   // display selection if requested
   if((piece->pipe->type & DT_DEV_PIXELPIPE_FULL)
      && g
-     && g->display_mask && self->dev->gui_attached
-     && (self == self->dev->gui_module) && (piece->pipe == self->dev->full.pipe))
+     && g->display_mask
+     && dt_iop_has_focus(self)
+     && (piece->pipe == self->dev->full.pipe))
     process_display(self, piece, ivoid, ovoid, roi_in, roi_out);
   else if(d->mode == DT_IOP_COLORZONES_MODE_SMOOTH)
     process_v3(self, piece, ivoid, ovoid, roi_in, roi_out);

src/iop/crop.c

@@ -166,12 +166,6 @@ dt_iop_colorspace_type_t default_colorspace(dt_iop_module_t *self,
   return IOP_CS_RGB;
 }
 
-static int _gui_has_focus(dt_iop_module_t *self)
-{
-  return (self->dev->gui_module == self
-          && dt_dev_modulegroups_test_activated(darktable.develop));
-}
-
 static void _commit_box(dt_iop_module_t *self,
                         dt_iop_crop_gui_data_t *g,
                         dt_iop_crop_params_t *p)
@@ -421,7 +415,7 @@ void commit_params(dt_iop_module_t *self,
   dt_iop_crop_params_t *p = (dt_iop_crop_params_t *)p1;
   dt_iop_crop_data_t *d = piece->data;
 
-  if(_gui_has_focus(self) && (pipe->type & DT_DEV_PIXELPIPE_BASIC))
+  if(dt_iop_has_focus(self) && (pipe->type & DT_DEV_PIXELPIPE_BASIC))
   {
     d->cx = 0.0f;
     d->cy = 0.0f;

src/iop/retouch.c

@@ -3860,9 +3860,7 @@ void process(dt_iop_module_t *self,
   retouch_user_data_t usr_data = { 0 };
   dwt_params_t *dwt_p = NULL;
 
-  const int gui_active = (self->dev) ? (self == self->dev->gui_module) : 0;
-  const gboolean display_wavelet_scale =
-    (g && gui_active) ? g->display_wavelet_scale : FALSE;
+  const gboolean display_wavelet_scale = g && dt_iop_has_focus(self) ? g->display_wavelet_scale : FALSE;
 
   // we will do all the clone, heal, etc on the input image,
   // this way the source for one algorithm can be the destination from a previous one
@@ -3881,8 +3879,7 @@ void process(dt_iop_module_t *self,
   usr_data.mask_display = FALSE;
   usr_data.suppress_mask = (g
                             && g->suppress_mask
-                            && self->dev->gui_attached
-                            && (self == self->dev->gui_module)
+                            && dt_iop_has_focus(self)
                             && (piece->pipe == self->dev->full.pipe));
   usr_data.display_scale = p->curr_scale;
 
@@ -3898,8 +3895,8 @@ void process(dt_iop_module_t *self,
 
   // check if this module should expose mask.
   if((piece->pipe->type & DT_DEV_PIXELPIPE_FULL) && g
-     && (g->mask_display || display_wavelet_scale) && self->dev->gui_attached
-     && (self == self->dev->gui_module) && (piece->pipe == self->dev->full.pipe))
+     && (g->mask_display || display_wavelet_scale)
+     && dt_iop_has_focus(self) && (piece->pipe == self->dev->full.pipe))
   {
     for(size_t j = 0; j < (size_t)roi_rt->width * roi_rt->height * 4; j += 4)
       in_retouch[j + 3] = 0.f;
@@ -3913,7 +3910,7 @@ void process(dt_iop_module_t *self,
   if(piece->pipe->type & DT_DEV_PIXELPIPE_FULL)
   {
     // check if the image support this number of scales
-    if(gui_active)
+    if(dt_iop_has_focus(self))
     {
       const int max_scales = dwt_get_max_scale(dwt_p);
       if(dwt_p->scales > max_scales)
@@ -4671,8 +4668,7 @@ int process_cl(dt_iop_module_t *self,
   retouch_user_data_t usr_data = { 0 };
   dwt_params_cl_t *dwt_p = NULL;
 
-  const gboolean gui_active = (self->dev) ? (self == self->dev->gui_module) : FALSE;
-  const gboolean display_wavelet_scale = g && gui_active ? g->display_wavelet_scale : FALSE;
+  const gboolean display_wavelet_scale = g && dt_iop_has_focus(self) ? g->display_wavelet_scale : FALSE;
 
   // we will do all the clone, heal, etc on the input image, this way
   // the source for one algorithm can be the destination from a
@@ -4696,8 +4692,7 @@ int process_cl(dt_iop_module_t *self,
   usr_data.mask_display = FALSE;
   usr_data.suppress_mask = (g
                             && g->suppress_mask
-                            && self->dev->gui_attached
-                            && (self == self->dev->gui_module)
+                            && dt_iop_has_focus(self)
                             && (piece->pipe == self->dev->full.pipe));
   usr_data.display_scale = p->curr_scale;
 
@@ -4718,8 +4713,7 @@ int process_cl(dt_iop_module_t *self,
   // check if this module should expose mask.
   if((piece->pipe->type & DT_DEV_PIXELPIPE_FULL)
      && g && g->mask_display
-     && self->dev->gui_attached
-     && (self == self->dev->gui_module)
+     && dt_iop_has_focus(self)
      && (piece->pipe == self->dev->full.pipe))
   {
     const int kernel = gd->kernel_retouch_clear_alpha;
@@ -4738,7 +4732,7 @@ int process_cl(dt_iop_module_t *self,
   if(piece->pipe->type & DT_DEV_PIXELPIPE_FULL)
   {
     // check if the image support this number of scales
-    if(gui_active)
+    if(dt_iop_has_focus(self))
     {
       const int max_scales = dwt_get_max_scale_cl(dwt_p);
       if(dwt_p->scales > max_scales)