glib: Use g_getenv everywhere instead of getenv

`getenv()` doesn't work well on Windows, f.ex., it can't fetch env
vars set with `SetEnvironmentVariable()`. This also means that it
doesn't work at all when targeting UWP since that's the only way to
set env vars in that case.

glib/gconvert.c

@@ -49,6 +49,7 @@
 #include "gthreadprivate.h"
 #include "gunicode.h"
 #include "gfileutils.h"
+#include "genviron.h"
 
 #include "glibintl.h"
 
@@ -1131,14 +1132,14 @@ g_get_filename_charsets (const gchar ***filename_charsets)
   if (!(cache->charset && strcmp (cache->charset, charset) == 0))
     {
       const gchar *new_charset;
-      gchar *p;
+      const gchar *p;
       gint i;
 
       g_free (cache->charset);
       g_strfreev (cache->filename_charsets);
       cache->charset = g_strdup (charset);
       
-      p = getenv ("G_FILENAME_ENCODING");
+      p = g_getenv ("G_FILENAME_ENCODING");
       if (p != NULL && p[0] != '\0') 
 	{
 	  cache->filename_charsets = g_strsplit (p, ",", 0);
@@ -1154,7 +1155,7 @@ g_get_filename_charsets (const gchar ***filename_charsets)
 		}
 	    }
 	}
-      else if (getenv ("G_BROKEN_FILENAMES") != NULL)
+      else if (g_getenv ("G_BROKEN_FILENAMES") != NULL)
 	{
 	  cache->filename_charsets = g_new0 (gchar *, 2);
 	  cache->is_utf8 = g_get_charset (&new_charset);

glib/giowin32.c

@@ -263,7 +263,7 @@ condition_to_string (GIOCondition condition)
 static gboolean
 g_io_win32_get_debug_flag (void)
 {
-  return (getenv ("G_IO_WIN32_DEBUG") != NULL);
+  return (g_getenv ("G_IO_WIN32_DEBUG") != NULL);
 }
 
 static void

glib/gmain.c

@@ -663,7 +663,7 @@ g_main_context_new (void)
   if (g_once_init_enter (&initialised))
     {
 #ifdef G_MAIN_POLL_DEBUG
-      if (getenv ("G_MAIN_POLL_DEBUG") != NULL)
+      if (g_getenv ("G_MAIN_POLL_DEBUG") != NULL)
         _g_main_poll_debug = TRUE;
 #endif
 

glib/gslice.c

@@ -364,7 +364,7 @@ slice_config_init (SliceConfig *config)
 
   *config = slice_config;
 
-  val = getenv ("G_SLICE");
+  val = g_getenv ("G_SLICE");
   if (val != NULL)
     {
       gint flags;

glib/gspawn-win32.c

@@ -72,7 +72,7 @@
       {							\
 	if (debug == -1)				\
 	  {						\
-	    if (getenv ("G_SPAWN_WIN32_DEBUG") != NULL)	\
+	    if (g_getenv ("G_SPAWN_WIN32_DEBUG") != NULL)	\
 	      debug = 1;				\
 	    else					\
 	      debug = 0;				\

glib/gtimezone.c

@@ -447,7 +447,7 @@ zone_info_unix (const gchar  *identifier,
   gchar *resolved_identifier = NULL;
   const gchar *tzdir;
 
-  tzdir = getenv ("TZDIR");
+  tzdir = g_getenv ("TZDIR");
   if (tzdir == NULL)
     tzdir = "/usr/share/zoneinfo";
 

glib/gwin32.c

@@ -109,7 +109,7 @@ g_win32_getlocale (void)
 {
   LCID lcid;
   LANGID langid;
-  gchar *ev;
+  const gchar *ev;
   gint primary, sub;
   char iso639[10];
   char iso3166[10];
@@ -120,9 +120,9 @@ g_win32_getlocale (void)
    * since GTK+ 2.10.7 setting either LC_ALL or LANG also sets the
    * Win32 locale and C library locale through code in gtkmain.c.
    */
-  if (((ev = getenv ("LC_ALL")) != NULL && ev[0] != '\0')
+  if (((ev = g_getenv ("LC_ALL")) != NULL && ev[0] != '\0')
-      || ((ev = getenv ("LC_MESSAGES")) != NULL && ev[0] != '\0')
+      || ((ev = g_getenv ("LC_MESSAGES")) != NULL && ev[0] != '\0')
-      || ((ev = getenv ("LANG")) != NULL && ev[0] != '\0'))
+      || ((ev = g_getenv ("LANG")) != NULL && ev[0] != '\0'))
     return g_strdup (ev);
 
   lcid = GetThreadLocale ();
@@ -1084,7 +1084,7 @@ g_win32_veh_handler (PEXCEPTION_POINTERS ExceptionInfo)
     case EXCEPTION_ILLEGAL_INSTRUCTION:
       break;
     default:
-      catch_list = getenv ("G_VEH_CATCH");
+      catch_list = g_getenv ("G_VEH_CATCH");
 
       while (!catch &&
              catch_list != NULL &&
@@ -1143,7 +1143,7 @@ g_win32_veh_handler (PEXCEPTION_POINTERS ExceptionInfo)
 
   fflush (stderr);
 
-  debugger_env = getenv ("G_DEBUGGER");
+  debugger_env = g_getenv ("G_DEBUGGER");
 
   if (debugger_env == NULL)
     return EXCEPTION_CONTINUE_SEARCH;
@@ -1173,7 +1173,7 @@ g_win32_veh_handler (PEXCEPTION_POINTERS ExceptionInfo)
                            NULL,
                            NULL,
                            TRUE,
-                           getenv ("G_DEBUGGER_OLD_CONSOLE") != NULL ? 0 : CREATE_NEW_CONSOLE,
+                           g_getenv ("G_DEBUGGER_OLD_CONSOLE") != NULL ? 0 : CREATE_NEW_CONSOLE,
                            NULL,
                            NULL,
                            &si,
@@ -1213,7 +1213,7 @@ g_crash_handler_win32_init (void)
    * break advanced exception handling such as in CLRs like C# or other managed
    * code. See: https://blogs.msdn.microsoft.com/jmstall/2006/05/24/beware-of-the-vectored-exception-handler-and-managed-code/
    */
-  if (getenv ("G_DEBUGGER") == NULL && getenv("G_VEH_CATCH") == NULL)
+  if (g_getenv ("G_DEBUGGER") == NULL && g_getenv("G_VEH_CATCH") == NULL)
     return;
 
   WinVEH_handle = AddVectoredExceptionHandler (0, &g_win32_veh_handler);