syntax: variable assignment can bypass cast

[nit.git] / src / syntax / control_flow.nit

diff --git a/src/syntax/control_flow.nit b/src/syntax/control_flow.nit
index f693eaa..4ac5723 100644 (file)
--- a/src/syntax/control_flow.nit
+++ b/src/syntax/control_flow.nit
@@ -144,11 +144,14 @@ abstract class VariableContext
                        if not is_set(v) and ctx.is_set(v) then
                                mark_is_set(v)
                        end
+                       var s = stype(v)
+                       var s1 = ctx.stype(v)
+                       if s1 != s then stype(v) = s1
                end
        end
 
        # Merge back two alternative flow context informations
-       meth merge2(ctx1, ctx2: VariableContext)
+       meth merge2(ctx1, ctx2, basectx: VariableContext)
        do
                if ctx1.unreash then
                        merge(ctx2)
@@ -159,6 +162,21 @@ abstract class VariableContext
                        if not is_set(v) and ctx1.is_set(v) and ctx2.is_set(v) then
                                mark_is_set(v)
                        end
+
+                       var s = stype(v)
+                       var s1 = ctx1.stype(v)
+                       var s2 = ctx2.stype(v)
+                       if s1 == s and s2 == s then
+                               # NOP
+                       else if s1 == s2 then
+                               stype(v) = s1
+                       else if s1 < s2 then
+                               stype(v) = s2
+                       else if s2 < s1 then
+                               stype(v) = s1
+                       else
+                               stype(v) = basectx.stype(v)
+                       end
                end
        end