Fix T52920: Saving Tiff Files type Blender crashes

Was only happening for 3 and 1 channel sources.

1 files changed, 34 insertions, 9 deletions

diff --git a/source/blender/imbuf/intern/tiff.c b/source/blender/imbuf/intern/tiff.c
index 8e5cf80e013..98aa7c5353b 100644
--- a/source/blender/imbuf/intern/tiff.c
+++ b/source/blender/imbuf/intern/tiff.c
@@ -813,26 +813,51 @@ int imb_savetiff(ImBuf *ibuf, const char *name, int flags)
 	}
 
 	/* copy pixel data.  While copying, we flip the image vertically. */
+	const int channels_in_float = ibuf->channels ? ibuf->channels : 4;
 	for (x = 0; x < ibuf->x; x++) {
 		for (y = 0; y < ibuf->y; y++) {
-			from_i = 4 * (y * ibuf->x + x);
+			from_i = ((size_t)channels_in_float) * (y * ibuf->x + x);
 			to_i   = samplesperpixel * ((ibuf->y - y - 1) * ibuf->x + x);
 
 			if (pixels16) {
 				/* convert from float source */
 				float rgb[4];
-				
-				if (ibuf->float_colorspace || (ibuf->colormanage_flag & IMB_COLORMANAGE_IS_DATA)) {
-					/* float buffer was managed already, no need in color space conversion */
-					copy_v3_v3(rgb, &fromf[from_i]);
+
+				if (channels_in_float == 3 || channels_in_float == 4) {
+					if (ibuf->float_colorspace ||
+					    (ibuf->colormanage_flag & IMB_COLORMANAGE_IS_DATA))
+					{
+						/* Float buffer was managed already, no need in color
+						 * space conversion.
+						 */
+						copy_v3_v3(rgb, &fromf[from_i]);
+					}
+					else {
+						/* Standard linear-to-srgb conversion if float buffer
+						 * wasn't managed.
+						 */
+						linearrgb_to_srgb_v3_v3(rgb, &fromf[from_i]);
+					}
+					if (channels_in_float == 4) {
+						rgb[3] = fromf[from_i + 3];
+					}
+					else {
+						rgb[3] = 1.0f;
+					}
 				}
 				else {
-					/* standard linear-to-srgb conversion if float buffer wasn't managed */
-					linearrgb_to_srgb_v3_v3(rgb, &fromf[from_i]);
+					if (ibuf->float_colorspace ||
+					    (ibuf->colormanage_flag & IMB_COLORMANAGE_IS_DATA))
+					{
+						rgb[0] = fromf[from_i];
+					}
+					else {
+						rgb[0] = linearrgb_to_srgb(fromf[from_i]);
+					}
+					rgb[1] = rgb[2] = rgb[0];
+					rgb[3] = 1.0f;
 				}
 
-				rgb[3] = fromf[from_i + 3];
-
 				for (i = 0; i < samplesperpixel; i++, to_i++)
 					to16[to_i] = FTOUSHORT(rgb[i]);
 			}