screenshot operator now adds file extension in the file selector and has its own save options rather then using the render options (works like image save a copy).

source/blender/blenkernel/BKE_image.h

@@ -68,6 +68,8 @@ char	BKE_imtype_valid_depths(const char imtype);
 
 char    BKE_imtype_from_arg(const char *arg);
 
+void    BKE_imformat_defaults(struct ImageFormatData *im_format);
+
 struct anim *openanim(const char *name, int flags, int streamindex);
 
 void	image_de_interlace(struct Image *ima, int odd);

source/blender/blenkernel/intern/image.c

@@ -1163,6 +1163,15 @@ int BKE_add_image_extension(char *string, const char imtype)
 	}
 }
 
+void BKE_imformat_defaults(ImageFormatData *im_format)
+{
+	memset(im_format, 0, sizeof(*im_format));
+	im_format->planes = R_IMF_PLANES_RGB;
+	im_format->imtype = R_IMF_IMTYPE_PNG;
+	im_format->quality = 90;
+	im_format->compress = 90;
+}
+
 /* could allow access externally - 512 is for long names, 64 is for id names */
 typedef struct StampData {
 	char 	file[512];

source/blender/editors/screen/screendump.c

@@ -56,6 +56,8 @@
 #include "RNA_access.h"
 #include "RNA_define.h"
 
+#include "UI_interface.h"
+
 #include "WM_types.h"
 #include "WM_api.h"
 
@@ -69,6 +71,8 @@ typedef struct ScreenshotData {
 	unsigned int *dumprect;
 	int dumpsx, dumpsy;
 	rcti crop;
+
+	ImageFormatData im_format;
 } ScreenshotData;
 
 /* get shot from frontbuffer */
@@ -113,9 +117,13 @@ static int screenshot_data_create(bContext *C, wmOperator *op)
 		scd->dumpsx= dumpsx;
 		scd->dumpsy= dumpsy;
 		scd->dumprect= dumprect;
-		if (sa)
+		if (sa) {
 			scd->crop= sa->totrct;
-		op->customdata= scd;
+		}
+
+		BKE_imformat_defaults(&scd->im_format);
+
+		op->customdata = scd;
 
 		return TRUE;
 	}
@@ -164,20 +172,13 @@ static int screenshot_exec(bContext *C, wmOperator *op)
 
 	if (scd) {
 		if (scd->dumprect) {
-			Scene *scene= CTX_data_scene(C);
 			ImBuf *ibuf;
 			char path[FILE_MAX];
 
 			RNA_string_get(op->ptr, "filepath", path);
-
-			BLI_strncpy(G.ima, path, sizeof(G.ima));
 			BLI_path_abs(path, G.main->name);
 
-			/* BKE_add_image_extension() checks for if extension was already set */
-			if (scene->r.scemode & R_EXTENSION)
-				if (strlen(path)<FILE_MAX-5)
-					BKE_add_image_extension(path, scene->r.im_format.imtype);
-
+			/* operator ensures the extension */
 			ibuf= IMB_allocImBuf(scd->dumpsx, scd->dumpsy, 24, 0);
 			ibuf->rect= scd->dumprect;
 
@@ -185,7 +186,11 @@ static int screenshot_exec(bContext *C, wmOperator *op)
 			if (!RNA_boolean_get(op->ptr, "full"))
 				screenshot_crop(ibuf, scd->crop);
 
-			BKE_write_ibuf(ibuf, path, &scene->r.im_format);
+			if (scd->im_format.planes == R_IMF_PLANES_BW) {
+				/* bw screenshot? - users will notice if it fails! */
+				IMB_color_to_bw(ibuf);
+			}
+			BKE_write_ibuf(ibuf, path, &scd->im_format);
 
 			IMB_freeImBuf(ibuf);
 		}
@@ -200,8 +205,9 @@ static int screenshot_invoke(bContext *C, wmOperator *op, wmEvent *UNUSED(event)
 	if (screenshot_data_create(C, op)) {
 		if (RNA_struct_property_is_set(op->ptr, "filepath"))
 			return screenshot_exec(C, op);
-		
-		RNA_string_set(op->ptr, "filepath", G.ima);
+
+		/* extension is added by 'screenshot_check' after */
+		RNA_string_set(op->ptr, "filepath", G.relbase_valid ? G.main->name : "//screen");
 		
 		WM_event_add_fileselect(C, op);
 	
@@ -210,21 +216,52 @@ static int screenshot_invoke(bContext *C, wmOperator *op, wmEvent *UNUSED(event)
 	return OPERATOR_CANCELLED;
 }
 
+static int screenshot_check(bContext *UNUSED(C), wmOperator *op)
+{
+	ScreenshotData *scd = op->customdata;
+	return WM_operator_filesel_ensure_ext_imtype(op, scd->im_format.imtype);
+}
+
 static int screenshot_cancel(bContext *UNUSED(C), wmOperator *op)
 {
 	screenshot_data_free(op);
 	return OPERATOR_CANCELLED;
 }
 
+static int screenshot_draw_check_prop(PointerRNA *UNUSED(ptr), PropertyRNA *prop)
+{
+	const char *prop_id = RNA_property_identifier(prop);
+
+	return !(strcmp(prop_id, "filepath") == 0);
+}
+
+static void screenshot_draw(bContext *UNUSED(C), wmOperator *op)
+{
+	uiLayout *layout = op->layout;
+	ScreenshotData *scd = op->customdata;
+	PointerRNA ptr;
+
+	/* image template */
+	RNA_pointer_create(NULL, &RNA_ImageFormatSettings, &scd->im_format, &ptr);
+	uiTemplateImageSettings(layout, &ptr);
+
+	/* main draw call */
+	RNA_pointer_create(NULL, op->type->srna, op->properties, &ptr);
+	uiDefAutoButsRNA(layout, &ptr, screenshot_draw_check_prop, '\0');
+}
+
+
 void SCREEN_OT_screenshot(wmOperatorType *ot)
 {
 	ot->name = "Save Screenshot"; /* weak: opname starting with 'save' makes filewindow give save-over */
 	ot->idname = "SCREEN_OT_screenshot";
 	
 	ot->invoke = screenshot_invoke;
+	ot->check = screenshot_check;
 	ot->exec = screenshot_exec;
-	ot->poll = WM_operator_winactive;
 	ot->cancel = screenshot_cancel;
+	ot->ui = screenshot_draw;
+	ot->poll = WM_operator_winactive;
 	
 	ot->flag = 0;
 	

source/blender/editors/space_image/image_ops.c

@@ -1001,11 +1001,7 @@ typedef struct {
 
 static void save_image_options_defaults(SaveImageOptions *simopts)
 {
-	memset(&simopts->im_format, 0, sizeof(simopts->im_format));
-	simopts->im_format.planes = R_IMF_PLANES_RGB;
-	simopts->im_format.imtype = R_IMF_IMTYPE_PNG;
-	simopts->im_format.quality = 90;
-	simopts->im_format.compress = 90;
+	BKE_imformat_defaults(&simopts->im_format);
 	simopts->filepath[0] = '\0';
 }
 
@@ -1246,13 +1242,7 @@ static int image_save_as_exec(bContext *C, wmOperator *op)
 static int image_save_as_check(bContext *UNUSED(C), wmOperator *op)
 {
 	ImageFormatData *imf = op->customdata;
-	char filepath[FILE_MAX];
-	RNA_string_get(op->ptr, "filepath", filepath);
-	if (BKE_add_image_extension(filepath, imf->imtype)) {
-		RNA_string_set(op->ptr, "filepath", filepath);
-		return TRUE;
-	}
-	return FALSE;
+	return WM_operator_filesel_ensure_ext_imtype(op, imf->imtype);
 }
 
 static int image_save_as_invoke(bContext *C, wmOperator *op, wmEvent *UNUSED(event))

source/blender/makesdna/DNA_scene_types.h

@@ -249,7 +249,7 @@ typedef struct ImageFormatData {
 	char depth;    /* bits per channel, R_IMF_CHAN_DEPTH_8 -> 32,
 	                * not a flag, only set 1 at a time */
 
-	char planes  ; /* - R_IMF_PLANES_BW, R_IMF_PLANES_RGB, R_IMF_PLANES_RGBA */
+	char planes;   /* - R_IMF_PLANES_BW, R_IMF_PLANES_RGB, R_IMF_PLANES_RGBA */
 	char flag;     /* generic options for all image types, alpha zbuffer */
 
 	char quality;  /* (0 - 100), eg: jpeg quality */

source/blender/windowmanager/WM_api.h

@@ -166,6 +166,7 @@ int			WM_enum_search_invoke(struct bContext *C, struct wmOperator *op, struct wm
 int			WM_operator_confirm		(struct bContext *C, struct wmOperator *op, struct wmEvent *event);
 		/* invoke callback, file selector "filepath" unset + exec */
 int			WM_operator_filesel		(struct bContext *C, struct wmOperator *op, struct wmEvent *event);
+int         WM_operator_filesel_ensure_ext_imtype(wmOperator *op, const char imtype);
 			/* poll callback, context checks */
 int			WM_operator_winactive	(struct bContext *C);
 			/* invoke callback, exec + redo popup */

source/blender/windowmanager/intern/wm_operators.c

@@ -65,6 +65,7 @@
 #include "BKE_context.h"
 #include "BKE_depsgraph.h"
 #include "BKE_idprop.h"
+#include "BKE_image.h"
 #include "BKE_library.h"
 #include "BKE_global.h"
 #include "BKE_main.h"
@@ -808,6 +809,22 @@ int WM_operator_filesel(bContext *C, wmOperator *op, wmEvent *UNUSED(event))
 	}
 }
 
+int WM_operator_filesel_ensure_ext_imtype(wmOperator *op, const char imtype)
+{
+	PropertyRNA *prop;
+	char filepath[FILE_MAX];
+	/* dont NULL check prop, this can only run on ops with a 'filepath' */
+	prop = RNA_struct_find_property(op->ptr, "filepath");
+	RNA_property_string_get(op->ptr, prop, filepath);
+	if (BKE_add_image_extension(filepath, imtype)) {
+		RNA_property_string_set(op->ptr, prop, filepath);
+		/* note, we could check for and update 'filename' here,
+		 * but so far nothing needs this. */
+		return TRUE;
+	}
+	return FALSE;
+}
+
 /* default properties for fileselect */
 void WM_operator_properties_filesel(wmOperatorType *ot, int filter, short type, short action, short flag, short display)
 {