fixed GetLongPath(): it never used ::GetLongPath() before and didn't work at all when called for the first time

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@33950 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

docs/changes.txt

@@ -26,7 +26,8 @@ wxMSW:
 - Worked around an apparent bug in deferred window positioning (moving a
   window from (x, y) to (a, b) and back to (x, y) misses the last step) by
   checking window positions against corresponding sizer state, if any.
-- A control's text colour now reflects the system colour setting.
+- A control's text colour now reflects the system colour setting again.
+- Fixed wxFileName::GetLongPath() to behave correctly during the first call too
 
 wxMac:
 

src/common/filename.cpp

@@ -1502,27 +1502,26 @@ wxString wxFileName::GetFullPath( wxPathFormat format ) const
 // Return the short form of the path (returns identity on non-Windows platforms)
 wxString wxFileName::GetShortPath() const
 {
-#if defined(__WXMSW__) && defined(__WIN32__) && !defined(__WXMICROWIN__) && !defined(__WXWINCE__)
     wxString path(GetFullPath());
-    wxString pathOut;
+
+#if defined(__WXMSW__) && defined(__WIN32__) && !defined(__WXMICROWIN__) && !defined(__WXWINCE__)
     DWORD sz = ::GetShortPathName(path, NULL, 0);
-    bool ok = sz != 0;
+    if ( sz != 0 )
-    if ( ok )
     {
-        ok = ::GetShortPathName
+        wxString pathOut;
+        if ( ::GetShortPathName
                (
                 path,
                 wxStringBuffer(pathOut, sz),
                 sz
-               ) != 0;
+               ) != 0 )
-    }
+        {
-    if (ok)
             return pathOut;
+        }
+    }
+#endif // Windows
 
     return path;
-#else
-    return GetFullPath();
-#endif
 }
 
 // Return the long form of the path (returns identity on non-Windows platforms)
@@ -1532,60 +1531,59 @@ wxString wxFileName::GetLongPath() const
              path = GetFullPath();
 
 #if defined(__WIN32__) && !defined(__WXMICROWIN__)
-    bool success = false;
 
 #if wxUSE_DYNAMIC_LOADER
     typedef DWORD (WINAPI *GET_LONG_PATH_NAME)(const wxChar *, wxChar *, DWORD);
 
+    // this is MT-safe as in the worst case we're going to resolve the function
+    // twice -- but as the result is the same in both threads, it's ok
+    static GET_LONG_PATH_NAME s_pfnGetLongPathName = NULL;
+    if ( !s_pfnGetLongPathName )
+    {
         static bool s_triedToLoad = false;
 
         if ( !s_triedToLoad )
         {
-        // suppress the errors about missing GetLongPathName[AW]
-        wxLogNull noLog;
-
             s_triedToLoad = true;
+
             wxDynamicLibrary dllKernel(_T("kernel32"));
-        if ( dllKernel.IsLoaded() )
+
-        {
-            // may succeed or fail depending on the Windows version
-            static GET_LONG_PATH_NAME s_pfnGetLongPathName = NULL;
 #ifdef _UNICODE
-            s_pfnGetLongPathName = (GET_LONG_PATH_NAME) dllKernel.GetSymbol(_T("GetLongPathNameW"));
+    #define ADD_STR_SFX(name) L#name L"W"
 #else
-            s_pfnGetLongPathName = (GET_LONG_PATH_NAME) dllKernel.GetSymbol(_T("GetLongPathNameA"));
+    #define ADD_STR_SFX(name) #name "A"
 #endif
 
+            if ( dllKernel.HasSymbol(ADD_STR_SFX(GetLongPathName)) )
+            {
+                s_pfnGetLongPathName = (GET_LONG_PATH_NAME)
+                    dllKernel.GetSymbol(ADD_STR_SFX(GetLongPathName));
+            }
+
+            // note that kernel32.dll can be unloaded, it stays in memory
+            // anyhow as all Win32 programs link to it and so it's safe to call
+            // GetLongPathName() even after unloading it
+        }
+    }
+
     if ( s_pfnGetLongPathName )
     {
         DWORD dwSize = (*s_pfnGetLongPathName)(path, NULL, 0);
-                bool ok = dwSize > 0;
+        if ( dwSize > 0 )
-
-                if ( ok )
         {
-                    DWORD sz = (*s_pfnGetLongPathName)(path, NULL, 0);
+            if ( (*s_pfnGetLongPathName)
-                    ok = sz != 0;
-                    if ( ok )
-                    {
-                        ok = (*s_pfnGetLongPathName)
                  (
                   path,
-                                wxStringBuffer(pathOut, sz),
+                  wxStringBuffer(pathOut, dwSize),
-                                sz
+                  dwSize
-                                ) != 0;
+                 ) != 0 )
-                        success = true;
+            {
-                    }
-                }
-            }
-        }
-    }
-
-    if (success)
                 return pathOut;
+            }
+        }
+    }
 #endif // wxUSE_DYNAMIC_LOADER
 
-    if (!success)
-    {
     // The OS didn't support GetLongPathName, or some other error.
     // We need to call FindFirstFile on each component in turn.
 
@@ -1642,7 +1640,6 @@ wxString wxFileName::GetLongPath() const
 
         ::FindClose(hFind);
     }
-    }
 #else // !Win32
     pathOut = path;
 #endif // Win32/!Win32