[gexiv2/wip/59: 3/4] win32: Handle non-unicode exiv2 case

[Jens Georg <jensgeorg src gnome org>]

commit 6bebb0e953dc7d7b9e43d4876e7a1245380d105f
Author: Jens Georg <mail jensge org>
Date:   Sat Nov 14 17:39:04 2020 +0100

    win32: Handle non-unicode exiv2 case
    
    If exiv2 is not compiled with windows unicode support, we need to
    convert the path to the locale from utf8.
    
    It can happen that this doesn't work (e.g. converting a russian filename
    on a german locale)
    
    Addresses #59

 gexiv2/gexiv2-metadata.cpp | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)
---
diff --git a/gexiv2/gexiv2-metadata.cpp b/gexiv2/gexiv2-metadata.cpp
index 21d47c1..33ab675 100644
--- a/gexiv2/gexiv2-metadata.cpp
+++ b/gexiv2/gexiv2-metadata.cpp
@@ -23,6 +23,10 @@
 #include <glib-object.h>
 #include <gio/gio.h>
 
+#ifdef G_OS_WIN32
+#include <glib/gwin32.h>
+#endif
+
 #include <exiv2/exiv2.hpp>
 
 #if EXIV2_TEST_VERSION(0,27,99)
@@ -376,8 +380,22 @@ gboolean gexiv2_metadata_open_path (GExiv2Metadata *self, const gchar *path, GEr
         }
         file.append(wfile);
         g_free(wfile);
+#else
+#ifdef G_OS_WIN32
+        char* local_path = g_win32_locale_filename_from_utf8(path);
+        if (local_path == nullptr) {
+            char *msg = g_strdup_printf("Failed to convert \"%s\" to locale \"%s\"", path, 
g_win32_getlocale());
+            g_set_error_literal(error, G_IO_ERROR, G_IO_ERROR_INVALID_FILENAME, msg);
+
+            g_free(msg);
+
+            return FALSE;
+        }
+        file = local_path;
+        g_free(local_path);
 #else
         file = path;
+#endif
 #endif
         self->priv->image = Exiv2::ImageFactory::open (file);