Merge branch 'filename-resolve-symlink'

Add wxFileName::ResolveLink().

See https://github.com/wxWidgets/wxWidgets/pull/2300

interface/wx/filename.h

@@ -266,8 +266,6 @@ wxULongLong wxInvalidSize;
     @li wxFileName::SetName()
     @li wxFileName::SetVolume()
 
-    You can initialize a wxFileName instance using one of the following functions:
-
 
     @section filename_operations File name operations
 
@@ -287,6 +285,24 @@ wxULongLong wxInvalidSize;
     @li wxFileName::Mkdir()
     @li wxFileName::Rmdir()
 
+    @section symlink_behavior Behavior with symlinks
+
+    wxFileName instances can store the path to symlinks on systems that support them.
+    When the path is for a symlink, the behavior of the following methods can be modified
+    to either operate on the symlink itself or on the file the link points to.
+
+    @li wxFileName::FileExists()
+    @li wxFileName::DirExists()
+    @li wxFileName::Exists()
+    @li wxFileName::SameAs()
+    @li wxFileName::GetTimes()
+
+    By default, those functions will operate on the target of the link, but they can be
+    made to operate on the link itself by calling wxFileName::DontFollowLink(). The current
+    link-following mode can be examined by calling wxFileName::ShouldFollowLink().
+
+    The wxFileName::ResolveLink() method can be used to get the absolute path for the target
+    of the symlink.
 
     @library{wxbase}
     @category{file}
@@ -1138,6 +1154,24 @@ public:
     */
     bool ReplaceHomeDir(wxPathFormat format = wxPATH_NATIVE);
 
+    /**
+        Find the absolute path of the file/directory that is pointed to by this
+        path.
+
+        If this path isn't a symlink, then this function will return the current
+        path. If the path does not exist on disk, An empty wxFileName instance
+        will be returned.
+
+        @note This is only supported on Unix-like platforms (e.g. wxGTK, wxOSX),
+              on other platforms (e.g. wxMSW) this function just returns the
+              current path.
+
+        @since 3.1.5
+
+        @return The absolute path that the current symlink path points to.
+    */
+    wxFileName ResolveLink();
+
 
     /**
         Deletes the specified directory from the file system.