PackageInstaller: Unbreak selecting custom install folders.

BFilePanel always sends B_CANCEL when it hides (as documented in the BeBook),
not just when the user cancels the file panel. Track what message we expect
and only react to B_CANCEL when it means the user really canceled selecting
the target folder.

src/apps/packageinstaller/PackageView.cpp

@@ -73,6 +73,7 @@ PackageView::PackageView(const entry_ref* ref)
 	BView("package_view", 0),
 	fOpenPanel(new BFilePanel(B_OPEN_PANEL, NULL, NULL, B_DIRECTORY_NODE,
 		false)),
+	fExpectingOpenPanelResult(false),
 	fInfo(ref),
 	fInstallProcess(this)
 {
@@ -180,6 +181,7 @@ PackageView::MessageReceived(BMessage* message)
 		}
 
 		case P_MSG_OPEN_PANEL:
+			fExpectingOpenPanelResult = true;
 			fOpenPanel->Show();
 			break;
 
@@ -266,6 +268,9 @@ PackageView::MessageReceived(BMessage* message)
 
 		case B_REFS_RECEIVED:
 		{
+			if (!_ValidateFilePanelMessage(message))
+				break;
+
 			entry_ref ref;
 			if (message->FindRef("refs", &ref) == B_OK) {
 				BPath path(&ref);
@@ -290,6 +295,9 @@ PackageView::MessageReceived(BMessage* message)
 
 		case B_CANCEL:
 		{
+			if (!_ValidateFilePanelMessage(message))
+				break;
+
 			// file panel aborted, select first suitable item
 			for (int32 i = 0; i < fDestination->CountItems(); i++) {
 				BMenuItem* item = fDestination->ItemAt(i);
@@ -723,3 +731,14 @@ PackageView::_AddMenuItem(const char* name, BMessage* message,
 	menu->AddItem(item);
 	return item;
 }
+
+
+bool
+PackageView::_ValidateFilePanelMessage(BMessage* message)
+{
+	if (!fExpectingOpenPanelResult)
+		return false;
+
+	fExpectingOpenPanelResult = false;
+	return true;
+}

src/apps/packageinstaller/PackageView.h

@@ -66,6 +66,8 @@ private:
 			BMenuItem*			_AddMenuItem(const char* name,
 									BMessage* message, BMenu* menu) const;
 
+			bool				_ValidateFilePanelMessage(BMessage* message);
+
 private:
 			BPopUpMenu*			fInstallTypes;
 			BTextView*			fInstallTypeDescriptionView;
@@ -74,6 +76,8 @@ private:
 			BButton*			fBeginButton;
 
 			BFilePanel*			fOpenPanel;
+			bool				fExpectingOpenPanelResult;
+
 			BPath				fCurrentPath;
 			uint32				fCurrentType;