FIX: crash when resolving file name containing a colon char on Posix systems

resolves: Oldes/Rebol-issues#2538

Author: Oldes

src/core/s-file.c

@@ -67,6 +67,7 @@
 	for (i = 0; i < len;) {
 		c = uni ? ((REBUNI*)bp)[i] : ((REBYTE*)bp)[i];
 		i++;
+#ifdef TO_WINDOWS
 		if (c == ':') {
 			// Handle the vol:dir/file format:
 			if (colon || slash) return 0; // no prior : or / allowed
@@ -77,7 +78,9 @@
 			}
 			c = '/'; // replace : with a /
 		}
-		else if (c == '\\' || c== '/') {
+		else
+#endif
+		if (c == '\\' || c== '/') {
 			if (slash > 0) continue;
 			c = '/';
 			slash = 1;

src/tests/units/file-test.r3

@@ -61,6 +61,17 @@ secure [%/ allow]
 	--assert %/rodan/shareddocs    = to-rebol-file "\\rodan\shareddocs"
 	--assert %/rodan/shareddocs/   = to-rebol-file "\\rodan\shareddocs\"
 
+if find [Linux macOS] system/platform [
+--test-- "issue-2538"
+	;@@ https://github.com/Oldes/Rebol-issues/issues/2538
+	cd (mkdir %issue-2538)
+	call/shell/wait "touch a:0:0"
+	--assert %a%3A0%3A0 == f: first read %.
+	--assert %a%3A0%3A0 == second split-path query/mode f 'name
+	delete f
+	cd ..
+]
+
 ===end-group===
 
 ===start-group=== "suffix?"