FIX: include TASK! evaluation only with INCLUDE_TASK define

... because TASK! is not implemented yet and causes crashes.

related to: Oldes/Rebol-issues#47

Author: Oldes

make/make-settings.r

@@ -17,6 +17,8 @@ Defines: [
 	USE_LZMA         ;-- adds support for LZMA [de]compression
 	USE_MIDI_DEVICE  ;-- includes MIDI device when possible (Windows & macOS)
 
+	;INCLUDE_TASK ;-- tasks are not implemented yet, so include it only on demand
+
 	;@@ optional fine tuning:
 	;DO_NOT_NORMALIZE_MAP_KEYS
 	; with above define you would get:

src/core/c-task.c

@@ -59,6 +59,7 @@
 
 #include "sys-core.h"
 
+#ifdef INCLUDE_TASK
 /***********************************************************************
 **
 */	static void Launch_Task(REBVAL *task)
@@ -76,13 +77,18 @@
 
 	Debug_Str("End Task");
 }
-
+#endif
 
 /***********************************************************************
 **
 */	void Do_Task(REBVAL *task)
 /*
 ***********************************************************************/
 {
+#ifdef INCLUDE_TASK
 	OS_CREATE_THREAD((void*)Launch_Task, task, 50000);
+#else 
+	puts("** Build using INCLUDE_TASK define to experiment with task!");
+	Trap0(RE_FEATURE_NA);
+#endif
 }

src/tests/run-tests.r3

@@ -46,6 +46,7 @@ dt [ ;- delta time
 	wrap load %units/typeset-test.r3
 	wrap load %units/datatype-test.r3
 	wrap load %units/parse-test.r3
+	wrap load %units/task-test.r3
 
 	recycle/torture
 	recycle

src/tests/units/task-test.r3

@@ -0,0 +1,18 @@
+Rebol [
+	Title:   "Rebol3 task test script"
+	Author:  "Oldes, Peter W A Wood"
+	File: 	 %task-test.r3
+	Tabs:	 4
+	Needs:   [%../quick-test-module.r3]
+]
+
+~~~start-file~~~ "TASK!"
+
+===start-group=== "task"
+	--test-- "issues-47"
+	;@@ https://github.com/Oldes/Rebol-issues/issues/47
+	--assert error? try [do make task! [2 / 0]] ; trying to evaluate a task should not crash!
+
+===end-group===
+
+~~~end-file~~~