corr bug due to the *** int<->uint problem

pub/src/expr.cpp

@@ -35,9 +35,10 @@ CContext::CContext( uint _k, uint _j, uint _i )
         return; // not sure whether k=-1 makes sense
 
     POlo f = NOlm::MOM[k];
-    if ( j==(uint)-1 && f->nJ()==1 )
-        j = 0;
-    else if ( j>=f->nJ() )
+    if ( j==(uint)-1 ) {
+        if ( f->nJ()==1 )
+            j = 0;
+    } else if ( j>=f->nJ() )
         throw "invalid evaluation context, j="+strg(j)+">=nJ="+strg(f->nJ());
 
     POld fd = P2D(f);