44271: Fix breaks propagated from until or return.

If the until or return test caused continuation but there was
a pending return, breaks didn't get cancelled causing enclosing
scope to skip commands.

ChangeLog

@@ -1,3 +1,9 @@
+2019-05-03  Peter Stephenson  <p.w.stephenson@ntlworld.com>
+
+	* 44271: Src/loop.c, Test/A01grammar.ztst: until with positive
+	and while with negative status propagated breaks too far after a
+	return, causing code in enclosing scope not to run.
+
 2019-04-26  dana  <dana@dana.is>
 
 	* 44234: Completion/Unix/Command/_ssh: Update for OpenSSH 8.0

Src/loop.c

@@ -425,7 +425,7 @@ execwhile(Estate state, UNUSED(int do_exec))
         breaks--;
 
         simple_pline = old_simple_pline;
-    } else
+    } else {
         for (;;) {
             state->pc = loop;
             noerrexit = NOERREXIT_EXIT | NOERREXIT_RETURN;
@@ -445,8 +445,11 @@ execwhile(Estate state, UNUSED(int do_exec))
 		    lastval = oldval;
                 break;
             }
-            if (retflag)
+            if (retflag) {
+		if (breaks)
+		    breaks--;
                 break;
+	    }
 
 	    /* In case the loop body is also a functional no-op,
 	     * make sure signal handlers recognize ^C as above. */
@@ -470,6 +473,7 @@ execwhile(Estate state, UNUSED(int do_exec))
             freeheap();
             oldval = lastval;
         }
+    }
     cmdpop();
     popheap();
     loops--;

Test/A01grammar.ztst

@@ -640,6 +640,16 @@
 >1
 >0
 
+  echo 'echo dot
+  until return 42; do
+    :
+  done' >until_dot
+  . ./until_dot
+  echo After dot
+0:return in positive until test in dot file does not cause excess breaks
+>dot
+>After dot
+
   echo 'echo $?' >dot_status
   false
   . ./dot_status