Cleanup: Add explicit defaults to MEM_new-allocated structs with no constructors.

While not strictly needed (currently!), relying on C++ 'default
initialization' is fragile and unreliable.

source/blender/editors/interface/eyedroppers/eyedropper_bone.cc

@@ -48,18 +48,18 @@ enum class SampleResult {
 };
 
 struct BoneDropper {
-  PointerRNA ptr;
-  PropertyRNA *prop;
-  PointerRNA search_ptr;
-  PropertyRNA *search_prop;
+  PointerRNA ptr = {};
+  PropertyRNA *prop = nullptr;
+  PointerRNA search_ptr = {};
+  PropertyRNA *search_prop = nullptr;
 
-  bool is_undo;
+  bool is_undo = false;
 
-  ScrArea *cursor_area; /* Area under the cursor. */
-  ARegionType *area_region_type;
-  void *draw_handle_pixel;
-  int name_pos[2];
-  char name[64];
+  ScrArea *cursor_area = nullptr; /* Area under the cursor. */
+  ARegionType *area_region_type = nullptr;
+  void *draw_handle_pixel = nullptr;
+  int name_pos[2] = {};
+  char name[64] = {};
 };
 
 struct BoneSampleData {

source/blender/editors/interface/eyedroppers/eyedropper_color.cc

@@ -60,28 +60,28 @@
 #include "eyedropper_intern.hh"
 
 struct Eyedropper {
-  ColorManagedDisplay *display;
+  ColorManagedDisplay *display = nullptr;
 
-  PointerRNA ptr;
-  PropertyRNA *prop;
-  int index;
-  bool is_undo;
+  PointerRNA ptr = {};
+  PropertyRNA *prop = nullptr;
+  int index = 0;
+  bool is_undo = false;
 
-  bool is_set;
-  float init_col[3]; /* for resetting on cancel */
+  bool is_set = false;
+  float init_col[3] = {}; /* for resetting on cancel */
 
-  bool accum_start; /* has mouse been pressed */
-  float accum_col[3];
-  int accum_tot;
+  bool accum_start = false; /* has mouse been pressed */
+  float accum_col[3] = {};
+  int accum_tot = 0;
 
-  wmWindow *cb_win;
-  int cb_win_event_xy[2];
-  void *draw_handle_sample_text;
-  char sample_text[MAX_NAME];
+  wmWindow *cb_win = nullptr;
+  int cb_win_event_xy[2] = {};
+  void *draw_handle_sample_text = nullptr;
+  char sample_text[MAX_NAME] = {};
 
-  bNode *crypto_node;
-  CryptomatteSession *cryptomatte_session;
-  ViewportColorSampleSession *viewport_session;
+  bNode *crypto_node = nullptr;
+  CryptomatteSession *cryptomatte_session = nullptr;
+  ViewportColorSampleSession *viewport_session = nullptr;
 };
 
 static void eyedropper_draw_cb(const wmWindow * /*window*/, void *arg)

source/blender/editors/interface/eyedroppers/eyedropper_colorband.cc

@@ -41,16 +41,16 @@
 namespace blender::ui {
 
 struct EyedropperColorband {
-  int event_xy_last[2];
+  int event_xy_last[2] = {};
   /* Alpha is currently fixed at 1.0, may support in future. */
-  Vector<float4> color_buffer;
-  bool sample_start;
-  ColorBand init_color_band;
-  ColorBand *color_band;
-  PointerRNA ptr;
-  PropertyRNA *prop;
-  bool is_undo;
-  bool is_set;
+  Vector<float4> color_buffer = {};
+  bool sample_start = false;
+  ColorBand init_color_band = {};
+  ColorBand *color_band = nullptr;
+  PointerRNA ptr = {};
+  PropertyRNA *prop = nullptr;
+  bool is_undo = false;
+  bool is_set = false;
 };
 
 /* For user-data only. */
@@ -105,7 +105,7 @@ static bool eyedropper_colorband_init(bContext *C, wmOperator *op)
     return false;
   }
 
-  EyedropperColorband *eye = MEM_new<EyedropperColorband>(__func__, EyedropperColorband{});
+  EyedropperColorband *eye = MEM_new<EyedropperColorband>(__func__);
   eye->color_band = band;
   eye->init_color_band = *eye->color_band;
   eye->ptr = rna_update_ptr;

source/blender/editors/interface/eyedroppers/eyedropper_datablock.cc

@@ -46,19 +46,19 @@
  * \note #DataDropper is only internal name to avoid confusion with other kinds of eye-droppers.
  */
 struct DataDropper {
-  PointerRNA ptr;
-  PropertyRNA *prop;
-  short idcode;
-  const char *idcode_name;
-  bool is_undo;
+  PointerRNA ptr = {};
+  PropertyRNA *prop = nullptr;
+  short idcode = 0;
+  const char *idcode_name = nullptr;
+  bool is_undo = false;
 
-  ID *init_id; /* for resetting on cancel */
+  ID *init_id = nullptr; /* for resetting on cancel */
 
-  ScrArea *cursor_area; /* Area under the cursor */
-  ARegionType *art;
-  void *draw_handle_pixel;
-  int name_pos[2];
-  char name[200];
+  ScrArea *cursor_area = nullptr; /* Area under the cursor */
+  ARegionType *art = nullptr;
+  void *draw_handle_pixel = nullptr;
+  int name_pos[2] = {};
+  char name[200] = {};
 };
 
 static void datadropper_draw_cb(const bContext * /*C*/, ARegion * /*region*/, void *arg)

source/blender/editors/interface/eyedroppers/eyedropper_depth.cc

@@ -49,21 +49,21 @@
  * \note #DepthDropper is only internal name to avoid confusion with other kinds of eye-droppers.
  */
 struct DepthDropper {
-  PointerRNA ptr;
-  PropertyRNA *prop;
-  bool is_undo;
+  PointerRNA ptr = {};
+  PropertyRNA *prop = nullptr;
+  bool is_undo = false;
 
-  bool is_set;
-  float init_depth; /* For resetting on cancel. */
+  bool is_set = false;
+  float init_depth = 0.0f; /* For resetting on cancel. */
 
-  bool accum_start; /* Has mouse been pressed. */
-  float accum_depth;
-  int accum_tot;
+  bool accum_start = false; /* Has mouse been pressed. */
+  float accum_depth = 0.0f;
+  int accum_tot = 0;
 
-  ARegionType *art;
-  void *draw_handle_pixel;
-  int name_pos[2];
-  char name[200];
+  ARegionType *art = nullptr;
+  void *draw_handle_pixel = nullptr;
+  int name_pos[2] = {};
+  char name[200] = {};
 };
 
 static void depthdropper_draw_cb(const bContext * /*C*/, ARegion * /*region*/, void *arg)

source/blender/editors/interface/eyedroppers/eyedropper_driver.cc

@@ -37,10 +37,10 @@
 
 struct DriverDropper {
   /* Destination property (i.e. where we'll add a driver) */
-  PointerRNA ptr;
-  PropertyRNA *prop;
-  int index;
-  bool is_undo;
+  PointerRNA ptr = {};
+  PropertyRNA *prop = nullptr;
+  int index = 0;
+  bool is_undo = false;
 
   /* TODO: new target? */
 };

source/blender/editors/interface/eyedroppers/eyedropper_grease_pencil_color.cc

@@ -61,17 +61,17 @@ enum class MaterialMode : int8_t {
 };
 
 struct EyedropperGreasePencil {
-  ColorManagedDisplay *display;
+  ColorManagedDisplay *display = nullptr;
 
-  bool accum_start; /* has mouse been pressed */
-  float3 accum_col;
-  int accum_tot;
-  float3 color;
+  bool accum_start = false; /* has mouse been pressed */
+  float3 accum_col = {};
+  int accum_tot = 0;
+  float3 color = {};
 
   /** Mode */
-  EyeMode mode;
+  EyeMode mode = EyeMode::Material;
   /** Material Mode */
-  MaterialMode mat_mode;
+  MaterialMode mat_mode = MaterialMode::Stroke;
 };
 
 /* Helper: Draw status message while the user is running the operator */