io.launcher: Bad usage of if-zero. Fixes #584.

basis/io/launcher/launcher.factor

@@ -159,7 +159,7 @@ M: process-failed error.
     ] [ process>> . ] bi ;
 
 : wait-for-success ( process -- )
-    dup wait-for-process [ drop ] [ process-failed ] if-zero ;
+    dup wait-for-process 0 = [ drop ] [ process-failed ] if ;
 
 : try-process ( desc -- )
     run-process wait-for-success ;

basis/io/launcher/windows/windows-tests.factor

@@ -2,7 +2,7 @@ USING: accessors arrays assocs calendar continuations
 environment eval hashtables io io.directories
 io.encodings.ascii io.files io.files.temp io.launcher
 io.launcher.windows io.pathnames kernel math namespaces parser
-sequences splitting system tools.test ;
+sequences splitting system tools.test combinators.short-circuit ;
 IN: io.launcher.windows.tests
 
 [ "hello world" ] [ { "hello" "world" } join-arguments ] unit-test
@@ -230,3 +230,14 @@ IN: io.launcher.windows.tests
     "vocab:io/launcher/windows/test/input.txt" >>stdin
     try-process
 ] unit-test
+
+! Regression
+[ "asdfdontexistplzplz" >process wait-for-success ]
+[
+    {
+        [ process-failed? ]
+        [ process>> process? ]
+        [ process>> command>> "asdfdontexistplzplz" = ]
+        [ process>> status>> f = ]
+    } 1&&
+] must-fail-with