gfileinfo: add file_path methods for language bindings

Including some tests by Philip Withnall.

docs/reference/gio/gio-sections-common.txt

@@ -391,6 +391,7 @@ g_file_info_get_attribute_status
 g_file_info_get_attribute_string
 g_file_info_get_attribute_stringv
 g_file_info_get_attribute_byte_string
+g_file_info_get_attribute_file_path
 g_file_info_get_attribute_boolean
 g_file_info_get_attribute_uint32
 g_file_info_get_attribute_int32
@@ -402,6 +403,7 @@ g_file_info_set_attribute_status
 g_file_info_set_attribute_string
 g_file_info_set_attribute_stringv
 g_file_info_set_attribute_byte_string
+g_file_info_set_attribute_file_path
 g_file_info_set_attribute_boolean
 g_file_info_set_attribute_uint32
 g_file_info_set_attribute_int32

gio/gfileinfo.c

@@ -966,6 +966,30 @@ g_file_info_get_attribute_byte_string (GFileInfo  *info,
   return _g_file_attribute_value_get_byte_string (value);
 }
 
+/**
+ * g_file_info_get_attribute_file_path:
+ * @info: a #GFileInfo.
+ * @attribute: a file attribute key.
+ *
+ * Gets the value of a byte string attribute as a file path.
+ *
+ * If the attribute does not contain a byte string, `NULL` will be returned.
+ *
+ * This function is meant to be used by language bindings that have specific
+ * handling for Unix paths.
+ *
+ * Returns: (type filename) (nullable): the contents of the @attribute value as
+ * a file path, or %NULL otherwise.
+ *
+ * Since: 2.78
+ **/
+const char *
+g_file_info_get_attribute_file_path (GFileInfo  *info,
+                                     const char *attribute)
+{
+  return g_file_info_get_attribute_byte_string (info, attribute);
+}
+
 /**
  * g_file_info_get_attribute_stringv:
  * @info: a #GFileInfo.
@@ -1318,6 +1342,28 @@ g_file_info_set_attribute_byte_string (GFileInfo  *info,
                                                 attr_value);
 }
 
+/**
+ * g_file_info_set_attribute_file_path:
+ * @info: a #GFileInfo.
+ * @attribute: a file attribute key.
+ * @attr_value: (type filename): a file path.
+ *
+ * Sets the @attribute to contain the given @attr_value,
+ * if possible.
+ *
+ * This function is meant to be used by language bindings that have specific
+ * handling for Unix paths.
+ *
+ * Since: 2.78
+ **/
+void
+g_file_info_set_attribute_file_path (GFileInfo  *info,
+                                     const char *attribute,
+                                     const char *attr_value)
+{
+  g_file_info_set_attribute_byte_string (info, attribute, attr_value);
+}
+
 void
 _g_file_info_set_attribute_boolean_by_id (GFileInfo *info,
                                           guint32    attribute,

gio/gfileinfo.h

@@ -1360,6 +1360,9 @@ GObject *          g_file_info_get_attribute_object      (GFileInfo  *info,
 GIO_AVAILABLE_IN_ALL
 char **            g_file_info_get_attribute_stringv     (GFileInfo  *info,
 							  const char *attribute);
+GIO_AVAILABLE_IN_2_78
+const char *       g_file_info_get_attribute_file_path   (GFileInfo  *info,
+							  const char *attribute);
 
 GIO_AVAILABLE_IN_ALL
 void               g_file_info_set_attribute             (GFileInfo  *info,
@@ -1402,6 +1405,10 @@ GIO_AVAILABLE_IN_ALL
 void               g_file_info_set_attribute_stringv     (GFileInfo  *info,
 							  const char *attribute,
 							  char      **attr_value);
+GIO_AVAILABLE_IN_2_78
+void               g_file_info_set_attribute_file_path   (GFileInfo  *info,
+							  const char *attribute,
+							  const char *attr_value);
 
 GIO_AVAILABLE_IN_ALL
 void               g_file_info_clear_status              (GFileInfo  *info);

gio/tests/g-file-info.c

@@ -43,7 +43,7 @@
 static void
 test_assigned_values (GFileInfo *info)
 {
-  const char *name, *display_name, *mistake;
+  const char *name, *name_filepath, *display_name, *mistake;
   guint64 size;
   GFileType type;
   
@@ -56,12 +56,14 @@ test_assigned_values (GFileInfo *info)
   /*  Retrieve data back and compare */
   
   name = g_file_info_get_attribute_byte_string (info, G_FILE_ATTRIBUTE_STANDARD_NAME);
+  name_filepath = g_file_info_get_attribute_file_path (info, G_FILE_ATTRIBUTE_STANDARD_NAME);
   display_name = g_file_info_get_attribute_string (info, G_FILE_ATTRIBUTE_STANDARD_DISPLAY_NAME);
   mistake = g_file_info_get_attribute_string (info, G_FILE_ATTRIBUTE_STANDARD_COPY_NAME);
   size = g_file_info_get_attribute_uint64 (info, G_FILE_ATTRIBUTE_STANDARD_SIZE);
   type = g_file_info_get_file_type (info);
   
   g_assert_cmpstr (name, ==, TEST_NAME);
+  g_assert_cmpstr (name_filepath, ==, name);
   g_assert_cmpstr (display_name, ==, TEST_DISPLAY_NAME);
   g_assert_null (mistake);
   g_assert_cmpint (size, ==, TEST_SIZE);
@@ -103,6 +105,11 @@ test_g_file_info (void)
 
   test_assigned_values (info);
 
+  /* Test the file path encoding functions */
+  g_file_info_set_attribute_file_path (info, G_FILE_ATTRIBUTE_STANDARD_NAME, "something different");
+  g_assert_cmpstr (g_file_info_get_attribute_file_path (info, G_FILE_ATTRIBUTE_STANDARD_NAME), ==, "something different");
+  g_file_info_set_attribute_file_path (info, G_FILE_ATTRIBUTE_STANDARD_NAME, TEST_NAME);
+
   /*  Test dups */
   info_dup = g_file_info_dup (info);
   g_assert_nonnull (info_dup);