FIX: special char escaping when molding a file (so it is backwards loadable)

resolves: Oldes/Rebol-issues#2491

Author: Oldes

src/core/s-mold.c

@@ -1597,6 +1597,9 @@ STOID Mold_Error(REBVAL *value, REB_MOLD *mold, REBFLG molded)
 	// so include also folowing chars for url escaping...
 	dc = b_cast("\x5C\x5E\x60\x7C\x7F");
 	for (c = (REBYTE)LEN_BYTES(dc); c > 0; c--) URL_Escapes[*dc++] = ESC_URL;
+	// required file escaping... https://github.com/Oldes/Rebol-issues/issues/2491
+	dc = b_cast("\x3A\x40\x5C\x5E\x7F");
+	for (c = (REBYTE)LEN_BYTES(dc); c > 0; c--) URL_Escapes[*dc++] = ESC_FILE;
 }
 
 

src/tests/units/mold-test.r3

@@ -198,6 +198,18 @@ Rebol [
 ===end-group=== 
 
 
+===start-group=== "mold file!"
+	
+	--test-- "mold file escaping"
+		;@@ https://github.com/Oldes/Rebol-issues/issues/2491
+		for i 0 255 1 [
+			f2: try [load mold f1: append copy %a to char! i]
+			--assert f1 == f2
+		]
+
+===end-group=== 
+
+
 ===start-group=== "mold-all"
 
 	--test-- "mold-true" --assert "true" = mold true