fix an (if... ) bug

src/kiss/Helpers.hx

@@ -7,6 +7,7 @@ import kiss.CompileError;
 import kiss.Types;
 
 using kiss.Reader;
+using kiss.Helpers;
 using StringTools;
 
 class Helpers {
@@ -85,10 +86,7 @@ class Helpers {
                 default:
                     throw CompileError.fromExp(argList, 'expected an argument list');
             },
-            expr: {
-                pos: Context.currentPos(),
-                expr: EReturn(convert(CallExp(Symbol("begin").withPos(body[0].pos), body).withPos(body[0].pos)))
-            }
+            expr: EReturn(convert(CallExp(Symbol("begin").withPos(body[0].pos), body).withPos(body[0].pos))).withContextPos()
         }
     }
 }

src/kiss/SpecialForms.hx

@@ -190,7 +190,13 @@ class SpecialForms {
 
             var condition = macro Prelude.truthy(${convert(args[0])});
             var thenExp = convert(args[1]);
-            var elseExp = if (args.length > 2) convert(args[2]) else null;
+            var elseExp = if (args.length > 2) {
+                convert(args[2]);
+            } else {
+                // Kiss (if... ) expressions all need to generate a Haxe else block
+                // to make sure they always return something
+                macro null;
+            };
 
             macro if ($condition)
                 $thenExp

src/test/cases/BasicTestCase.hx

@@ -120,6 +120,8 @@ class BasicTestCase extends Test {
         Assert.equals(false, BasicTestCase.myIf8);
         Assert.equals(false, BasicTestCase.myIf9);
         Assert.equals(true, BasicTestCase.myIf10);
+        Assert.equals(5, BasicTestCase.myIf11);
+        Assert.equals(null, BasicTestCase.myIf12);
     }
 
     function testMacros() {

src/test/cases/BasicTestCase.kiss

@@ -64,6 +64,8 @@
 (defvar myIf8 (if "" true false))
 (defvar myIf9 (if [] true false))
 (defvar myIf10 (if [1] true false))
+(defvar myIf11 (if true 5))
+(defvar myIf12 (if false 5))
 
 (defvar :Int myInt 8)