Make sure bool will always have the same size in C and C++

There were an issues with data structures defined in headers
and being used by both C and C++ on systems with stdbool
unavailable.

This happened because bool in this case will be defined as
unsigned int, which is 4 bytes. But C++'s bool is only 1
byte and this lead to alignment issues.

Now bool is always 1 byte, also made sure there's no situation
like bool foo = BitField & BitFlag, which could give overflow
issues. Use (BitField & BitFlag) != 0 instead.

Fixes #35553: Compositor broken (Backdrop & Preview)

source/blender/blenlib/BLI_sys_types.h

@@ -119,11 +119,8 @@ typedef uint64_t u_int64_t;
 #  ifdef __cplusplus
 typedef bool _BLI_Bool;
 #  else
-/* using char here may cause nasty tricky bugs, e.g.
- *     bool is_bit_flag = RNA_property_flag(prop) & PROP_ENUM_FLAG;
- * as PROP_ENUM_FLAG is farther than 8th bit, do_translate would be always false!
- */
-#   define _BLI_Bool unsigned int
+/* Make sure bool is alays defined with the same size for both C and C++ */
+#   define _BLI_Bool unsigned char
 #  endif
 # else
 #  define _BLI_Bool _Bool

source/blender/bmesh/intern/bmesh_mesh.c

@@ -573,7 +573,7 @@ void BM_mesh_elem_index_validate(BMesh *bm, const char *location, const char *fu
 	bool is_any_error = 0;
 
 	for (i = 0; i < 3; i++) {
-		const bool is_dirty = (flag_types[i] & bm->elem_index_dirty);
+		const bool is_dirty = (flag_types[i] & bm->elem_index_dirty) != 0;
 		int index = 0;
 		bool is_error = false;
 		int err_val = 0;

source/blender/editors/animation/anim_draw.c

@@ -399,9 +399,9 @@ float ANIM_unit_mapping_get_factor(Scene *scene, ID *id, FCurve *fcu, short rest
 static short bezt_unit_mapping_apply(KeyframeEditData *ked, BezTriple *bezt)
 {
 	/* mapping factor is stored in f1, flags are stored in i1 */
-	const bool only_keys = (ked->i1 & ANIM_UNITCONV_ONLYKEYS);
-	const bool sel_vs = (ked->i1 & ANIM_UNITCONV_SELVERTS);
-	const bool skip_knot = (ked->i1 & ANIM_UNITCONV_SKIPKNOTS);
+	const bool only_keys = (ked->i1 & ANIM_UNITCONV_ONLYKEYS) != 0;
+	const bool sel_vs = (ked->i1 & ANIM_UNITCONV_SELVERTS) != 0;
+	const bool skip_knot = (ked->i1 & ANIM_UNITCONV_SKIPKNOTS) != 0;
 	float fac = ked->f1;
 	
 	/* adjust BezTriple handles only if allowed to */

source/blender/editors/interface/interface_widgets.c

@@ -3411,7 +3411,7 @@ void ui_draw_but(const bContext *C, ARegion *ar, uiStyle *style, uiBut *but, rct
 	if (wt) {
 		//rcti disablerect = *rect; /* rect gets clipped smaller for text */
 		int roundboxalign, state;
-		bool disabled = FALSE;
+		bool disabled = false;
 		
 		roundboxalign = widget_roundbox_set(but, rect);
 
@@ -3420,7 +3420,7 @@ void ui_draw_but(const bContext *C, ARegion *ar, uiStyle *style, uiBut *but, rct
 		
 		if (state & (UI_BUT_DISABLED | UI_BUT_INACTIVE))
 			if (but->dt != UI_EMBOSSP)
-				disabled = TRUE;
+				disabled = true;
 		
 		if (disabled)
 			ui_widget_color_disabled(wt);

source/blender/editors/space_buttons/buttons_texture.c

@@ -258,7 +258,7 @@ static void buttons_texture_users_from_context(ListBase *users, const bContext *
 	World *wrld = NULL;
 	Brush *brush = NULL;
 	ID *pinid = sbuts->pinid;
-	bool limited_mode = sbuts->flag & SB_TEX_USER_LIMITED;
+	bool limited_mode = (sbuts->flag & SB_TEX_USER_LIMITED) != 0;
 
 	/* get data from context */
 	if (pinid) {

source/blender/editors/space_view3d/view3d_fly.c

@@ -1086,7 +1086,7 @@ static int flyApply_ndof(bContext *C, FlyInfo *fly)
 
 #if 0
 	bool do_rotate = (flag & NDOF_SHOULD_ROTATE) && (fly->pan_view == false);
-	bool do_translate = (flag & (NDOF_SHOULD_PAN | NDOF_SHOULD_ZOOM));
+	bool do_translate = (flag & (NDOF_SHOULD_PAN | NDOF_SHOULD_ZOOM)) != 0;
 #endif
 
 	bool do_rotate = (fly->pan_view == false);

source/blender/imbuf/intern/png.c

@@ -132,7 +132,7 @@ int imb_savepng(struct ImBuf *ibuf, const char *name, int flags)
 	int i, bytesperpixel, color_type = PNG_COLOR_TYPE_GRAY;
 	FILE *fp = NULL;
 
-	bool is_16bit  = (ibuf->ftype & PNG_16BIT);
+	bool is_16bit  = (ibuf->ftype & PNG_16BIT) != 0;
 	bool has_float = (ibuf->rect_float != NULL);
 	int channels_in_float = ibuf->channels ? ibuf->channels : 4;
 

source/blender/modifiers/intern/MOD_bevel.c

@@ -110,7 +110,7 @@ static DerivedMesh *applyModifier(ModifierData *md, struct Object *ob,
 	MDeformVert *dvert = NULL;
 	BevelModifierData *bmd = (BevelModifierData *) md;
 	const float threshold = cosf((bmd->bevel_angle + 0.00001f) * (float)M_PI / 180.0f);
-	const bool vertex_only = bmd->flags & BME_BEVEL_VERT;
+	const bool vertex_only = (bmd->flags & BME_BEVEL_VERT) != 0;
 	const bool do_clamp = !(bmd->flags & BME_BEVEL_OVERLAP_OK);
 
 	bm = DM_to_bmesh(dm);

source/blender/render/intern/source/pipeline.c

@@ -472,7 +472,7 @@ void RE_FreePersistentData(void)
 /* disprect is optional, if NULL it assumes full window render */
 void RE_InitState(Render *re, Render *source, RenderData *rd, SceneRenderLayer *srl, int winx, int winy, rcti *disprect)
 {
-	bool had_freestyle = (re->r.mode & R_EDGE_FRS);
+	bool had_freestyle = (re->r.mode & R_EDGE_FRS) != 0;
 
 	re->ok = TRUE;   /* maybe flag */