When we call a gosub routine, the variables should be scoped to avoid contaminating the caller.

This affected the ~~EXTEN~~ hack, where a subroutine might have changed the
value before it was used in the caller.
Patch by myself, tested by ebroad on #asterisk


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@222273 65c4cc65-6c06-0410-ace0-fbb531ad65f3

res/ael/pval.c

@@ -3361,6 +3361,7 @@ static void gen_prios(struct ael_extension *exten, char *label, pval *statement,
 		if (contains_switch(statement)) { /* only run contains_switch if you haven't checked before */
 			if (mother_exten) {
 				if (!mother_exten->has_switch) {
+					for (first = 1; first >= 0; first--) {
 						switch_set = new_prio();
 						switch_set->type = AEL_APPCALL;
 						if (!ast_compat_app_set) {
@@ -3368,7 +3369,16 @@ static void gen_prios(struct ael_extension *exten, char *label, pval *statement,
 						} else {
 							switch_set->app = strdup("Set");
 						}
+						/* Are we likely inside a gosub subroutine? */
+						if (!strcmp(mother_exten->name, "s") && first) {
+							/* If we're not actually within a gosub, this will fail, but the
+							 * second time through, it will get set.  If we are within gosub,
+							 * the second time through is redundant, but acceptable. */
+							switch_set->appargs = strdup("LOCAL(~~EXTEN~~)=${EXTEN}");
+						} else {
 							switch_set->appargs = strdup("~~EXTEN~~=${EXTEN}");
+							first = 0;
+						}
 						linkprio(exten, switch_set, mother_exten);
 						mother_exten->has_switch = 1;
 						mother_exten->checked_switch = 1;
@@ -3377,8 +3387,10 @@ static void gen_prios(struct ael_extension *exten, char *label, pval *statement,
 							exten->checked_switch = 1;
 						}
 					}
+				}
 			} else if (exten) {
 				if (!exten->has_switch) {
+					for (first = 1; first >= 0; first--) {
 						switch_set = new_prio();
 						switch_set->type = AEL_APPCALL;
 						if (!ast_compat_app_set) {
@@ -3386,7 +3398,16 @@ static void gen_prios(struct ael_extension *exten, char *label, pval *statement,
 						} else {
 							switch_set->app = strdup("Set");
 						}
+						/* Are we likely inside a gosub subroutine? */
+						if (!strcmp(exten->name, "s")) {
+							/* If we're not actually within a gosub, this will fail, but the
+							 * second time through, it will get set.  If we are within gosub,
+							 * the second time through is redundant, but acceptable. */
+							switch_set->appargs = strdup("LOCAL(~~EXTEN~~)=${EXTEN}");
+						} else {
 							switch_set->appargs = strdup("~~EXTEN~~=${EXTEN}");
+							first = 0;
+						}
 						linkprio(exten, switch_set, mother_exten);
 						exten->has_switch = 1;
 						exten->checked_switch = 1;
@@ -3396,6 +3417,7 @@ static void gen_prios(struct ael_extension *exten, char *label, pval *statement,
 						}
 					}
 				}
+			}
 		} else {
 			if (mother_exten) {
 				mother_exten->checked_switch = 1;