FIX: throw error on invalid image! construction syntax

related to: Oldes/Rebol-issues#1034

Author: Oldes

src/core/t-image.c

@@ -637,7 +637,7 @@ INLINE REBCNT ARGB_To_BGR(REBCNT i)
 		if ((w = Valid_Tuples(block))) Trap_Arg(block+w-1);
 		Tuples_To_RGBA(ip, size, VAL_BLK_DATA(block), VAL_LEN(block));
 	}
-	else if (!IS_END(block)) return 0;
+	if (!IS_END(block)) return 0;
 
 	//if (!IS_END(block)) Trap_Arg(block);
 

src/tests/units/image-test.r3

@@ -22,6 +22,42 @@ Rebol [
 		--assert-er try [image? to image! make gob! []]
 ===end-group===
 
+===start-group=== "construct image"
+	--test-- "construct image valid"
+		--assert "make image! [1x1 #{FFFFFF}]" = mold #[image! 1x1]
+		--assert "make image! [1x1 #{FFFFFF}]" = mold #[image! 1x1 #{FFFFFF}]
+		--assert "make image! [1x1 #{FFFFFF}]" = mold #[image! 1x1 #{FF}]
+		--assert "make image! [1x1 #{141414}]" = mold #[image! 1x1 20.20.20]
+		--assert "make image! [1x1 #{141414} #{3C}]" = mold #[image! 1x1 20.20.20.60]
+		--assert all [
+			"make image! [1x1 #{FFFFFF} #{30}]" = mold img: #[image! 1x1 #{FFFFFF} #{30}]
+			#{30} = img/alpha
+			#{FFFFFF} = img/rgb
+			#{FFFFFF30} = img/rgba
+		]
+		--assert all [
+			"make image! [1x1 #{}]" = mold img: #[image! 1x1 #{FFFFFF} 2]
+			2 = index? img
+			#{} = img/alpha
+			#{} = img/rgba
+			img: head img
+			"make image! [1x1 #{FFFFFF}]" = mold img
+			#{FF} = img/alpha
+			#{FFFFFFFF} = img/rgba
+		]
+	--test-- "construct image invalid"
+		;@@ https://github.com/Oldes/Rebol-issues/issues/1034
+		--assert error? try [load {#[image!]}]
+		--assert error? try [load {#[image! x]}]
+		--assert error? try [load {#[image! 1x-1]}]
+		--assert error? try [load {#[image! 1x1 x]}]
+		--assert error? try [load {#[image! 1x1 #{FF} x]}]
+		--assert error? try [load {#[image! 1x1 20.20.20.60 x]}]
+		--assert error? try [load {#[image! 1x1 #{FFFFFF} #{30} x]}]
+
+
+===end-group===
+
 ===start-group=== "FOREACH"
 	--test-- "issue-1479"
 	;@@ https://github.com/Oldes/Rebol-issues/issues/1479