PathChooser: Trigger revalidation when environment or base name change

Trigger a re-evaluation of the state when the base filename or the
environment changes. Both can effect whether a command is found or
not.

Change-Id: I3fcb9683296113e04f7a78bb2d3ae681f6603823
Reviewed-by: Daniel Teske <daniel.teske@digia.com>

src/libs/utils/pathchooser.cpp

@@ -302,15 +302,18 @@ FileName PathChooser::baseFileName() const
 void PathChooser::setBaseFileName(const FileName &base)
 {
     d->m_baseDirectory = base.toString();
+    triggerChanged();
 }
 
 void PathChooser::setEnvironment(const Utils::Environment &env)
 {
     QString oldExpand = path();
     d->m_environment = env;
-    if (path() != oldExpand)
+    if (path() != oldExpand) {
+        triggerChanged();
         emit changed(rawPath());
     }
+}
 
 QString PathChooser::path() const
 {