Fixing and upgrading Fl_Preferences (#374)

* Added filename function to Fl_Preferences

Static function to get filename before opening.
Member to get filename after opening.
Bug fixes for memory mapped preferences.

* ERROR is a macro on Windows, don't use it

* Added Fl_Preferences::dirty().

User can now check if the database will be written
when flushed or destroyed.
Flush returns a crude error code.

* Fl_Preferences::get binary data returns # of bytes read.

* Verified group deletion code

* Fl_Preferences ignores locale.

This will make .prefs files interchangeable
between different computers.

* Updating the Preferences Mode to ignore locale.

* Fixes in docs.

2 files changed, 41 insertions, 2 deletions

diff --git a/src/drivers/X11/Fl_X11_System_Driver.H b/src/drivers/X11/Fl_X11_System_Driver.H
index 146a48e83..891c14d16 100644
--- a/src/drivers/X11/Fl_X11_System_Driver.H
+++ b/src/drivers/X11/Fl_X11_System_Driver.H
@@ -31,6 +31,8 @@ public:
   virtual void display_arg(const char *arg);
   virtual int XParseGeometry(const char*, int*, int*, unsigned int*, unsigned int*);
   virtual int clocale_printf(FILE *output, const char *format, va_list args);
+  virtual int clocale_snprintf(char *output, size_t output_size, const char *format, va_list args);
+  virtual int clocale_sscanf(const char *input, const char *format, va_list args);
   // these 2 are in Fl_get_key.cxx
   virtual int event_key(int k);
   virtual int get_key(int k);
diff --git a/src/drivers/X11/Fl_X11_System_Driver.cxx b/src/drivers/X11/Fl_X11_System_Driver.cxx
index fcd1d2d5e..2f3656a47 100644
--- a/src/drivers/X11/Fl_X11_System_Driver.cxx
+++ b/src/drivers/X11/Fl_X11_System_Driver.cxx
@@ -79,10 +79,15 @@ Fl_System_Driver *Fl_System_Driver::newSystemDriver()
   return new Fl_X11_System_Driver();
 }
 
+#if defined(__linux__) && defined(_XOPEN_SOURCE) && _XOPEN_SOURCE >= 700
+static locale_t c_locale = NULL;
+#endif
+
 
 int Fl_X11_System_Driver::clocale_printf(FILE *output, const char *format, va_list args) {
 #if defined(__linux__) && defined(_XOPEN_SOURCE) && _XOPEN_SOURCE >= 700
-  static locale_t c_locale = newlocale(LC_NUMERIC_MASK, "C", duplocale(LC_GLOBAL_LOCALE));
+  if (!c_locale)
+    c_locale = newlocale(LC_NUMERIC_MASK, "C", duplocale(LC_GLOBAL_LOCALE));
   locale_t previous_locale = uselocale(c_locale);
   int retval = vfprintf(output, format, args);
   uselocale(previous_locale);
@@ -95,6 +100,35 @@ int Fl_X11_System_Driver::clocale_printf(FILE *output, const char *format, va_li
   return retval;
 }
 
+int Fl_X11_System_Driver::clocale_snprintf(char *output, size_t output_size, const char *format, va_list args) {
+#if defined(__linux__) && defined(_XOPEN_SOURCE) && _XOPEN_SOURCE >= 700
+  if (!c_locale)
+    c_locale = newlocale(LC_NUMERIC_MASK, "C", duplocale(LC_GLOBAL_LOCALE));
+  locale_t previous_locale = uselocale(c_locale);
+  int retval = vsnprintf(output, output_size, format, args);
+  uselocale(previous_locale);
+#else
+  char *saved_locale = setlocale(LC_NUMERIC, NULL);
+  setlocale(LC_NUMERIC, "C");
+  int retval = vsnprintf(output, output_size, format, args);
+  setlocale(LC_NUMERIC, saved_locale);
+#endif
+}
+
+int Fl_X11_System_Driver::clocale_sscanf(const char *input, const char *format, va_list args) {
+#if defined(__linux__) && defined(_XOPEN_SOURCE) && _XOPEN_SOURCE >= 700
+  if (!c_locale)
+    c_locale = newlocale(LC_NUMERIC_MASK, "C", duplocale(LC_GLOBAL_LOCALE));
+  locale_t previous_locale = uselocale(c_locale);
+  int retval = vsscanf(input, format, args);
+  uselocale(previous_locale);
+#else
+  char *saved_locale = setlocale(LC_NUMERIC, NULL);
+  setlocale(LC_NUMERIC, "C");
+  int retval = vsscanf(input, format, args);
+  setlocale(LC_NUMERIC, saved_locale);
+#endif
+}
 
 // Find a program in the path...
 static char *path_find(const char *program, char *filename, int filesize) {
@@ -415,7 +449,10 @@ void Fl_X11_System_Driver::newUUID(char *uuidBuffer)
           b[8], b[9], b[10], b[11], b[12], b[13], b[14], b[15]);
 }
 
-char *Fl_X11_System_Driver::preference_rootnode(Fl_Preferences *prefs, Fl_Preferences::Root root, const char *vendor,
+/*
+ Note: `prefs` can be NULL!
+ */
+char *Fl_X11_System_Driver::preference_rootnode(Fl_Preferences * /*prefs*/, Fl_Preferences::Root root, const char *vendor,
                                                 const char *application)
 {
   static char *filename = 0L;