Bug1217: Export "other uncompressed files" now uses correct default extension...

... but there is this consequence:  If you do type an explicit extension,
which is one of the acceptable extensions though different from the
"Header:" chocie, then it is also corrected, silently.  This behavior is
different from other cases where the user types an inappropriate explicit
extension and is prompted to fix it.

src/export/Export.cpp

@@ -185,7 +185,7 @@ wxString ExportPlugin::GetMask(int index)
    wxString mask = GetDescription(index) + wxT("|");
 
    // Build the mask
-   wxString ext = GetExtension(index);
+   // wxString ext = GetExtension(index);
    wxArrayString exts = GetExtensions(index);
    for (size_t i = 0; i < exts.GetCount(); i++) {
       mask += wxT("*.") + exts[i] + wxT(";");

src/export/Export.h

@@ -38,7 +38,7 @@ class AUDACITY_DLL_API FormatInfo
       ~FormatInfo(){};
       wxString mFormat;
       wxString mDescription;
-      wxString mExtension;
+      // wxString mExtension;
       wxArrayString mExtensions;
       wxString mMask;
       int mMaxChannels;

src/export/ExportPCM.cpp

@@ -168,6 +168,7 @@ ExportPCMOptions::ExportPCMOptions(wxWindow *parent, int selformat)
    PopulateOrExchange(S);
 
    TransferDataToWindow();
+   TransferDataFromWindow();
 }
 
 ExportPCMOptions::~ExportPCMOptions()
@@ -268,6 +269,8 @@ void ExportPCMOptions::OnHeaderChoice(wxCommandEvent & WXUNUSED(evt))
    mEncodingFromChoice = sel;
    mEncodingChoice->SetSelection(sel);
    ValidatePair(GetFormat());
+
+   TransferDataFromWindow();
 }
 
 int ExportPCMOptions::GetFormat()
@@ -320,7 +323,8 @@ public:
                Tags *metadata = NULL,
                int subformat = 0);
    // optional
-   wxString GetExtension(int index = WXSIZEOF(kFormats));
+   wxString GetExtension(int index);
+   virtual bool CheckFileName(wxFileName &filename, int format);
 
 private:
 
@@ -894,6 +898,24 @@ wxString ExportPCM::GetExtension(int index)
    }
 }
 
+bool ExportPCM::CheckFileName(wxFileName &filename, int format)
+{
+   if (format == WXSIZEOF(kFormats) &&
+       IsExtension(filename.GetExt(), format)) {
+      // PRL:  Bug1217
+      // If the user left the extension blank, then the
+      // file dialog will have defaulted the extension, beyond our control,
+      // to the first in the wildcard list or (Linux) the last-saved extension,
+      // ignoring what we try to do with the additional drop-down mHeaderChoice.
+      // Here we can intercept file name processing and impose the correct default.
+      // However this has the consequence that in case an explicit extension was typed,
+      // we override it without asking.
+      filename.SetExt(GetExtension(format));
+   }
+
+   return ExportPlugin::CheckFileName(filename, format);
+}
+
 ExportPlugin *New_ExportPCM()
 {
    return new ExportPCM();