Use long path prefix in osl_getFileStatus

When installing an extension e.g., paths can get very long and they
hit the 255 char limit, thus the installation fails.
So we need to prefix the path with the long file name prefix
when its longer than MAX_PATH for windows api calls to succeed.

Change-Id: Ie62644192ba40a9d4802772cd9837fc84fae947a
Reviewed-on: https://gerrit.libreoffice.org/50079Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Mike Kaganski <mike.kaganski@collabora.com>

sal/osl/w32/file_dirvol.cxx

@@ -1573,9 +1573,16 @@ oslFileError SAL_CALL osl_getFileStatus(
         break;
     }
 
+    OUString sFullPath(pItemImpl->m_pFullPath);
+
+    // Prefix long paths, windows API calls expect this prefix
+    // (only local paths starting with something like C: or D:)
+    if (sFullPath.getLength() >= MAX_PATH && isalpha(sFullPath[0]) && sFullPath[1] == ':')
+        sFullPath = "\\\\?\\" + sFullPath;
+
     if ( uFieldMask & osl_FileStatus_Mask_Validate )
     {
-        HANDLE  hFind = FindFirstFileW( o3tl::toW(rtl_uString_getStr( pItemImpl->m_pFullPath )), &pItemImpl->FindData );
+        HANDLE  hFind = FindFirstFileW( o3tl::toW(sFullPath.getStr() ), &pItemImpl->FindData );
 
         if ( hFind != INVALID_HANDLE_VALUE )
             FindClose( hFind );
@@ -1635,7 +1642,7 @@ oslFileError SAL_CALL osl_getFileStatus(
 
     if ( uFieldMask & osl_FileStatus_Mask_LinkTargetURL )
     {
-        oslFileError error = osl_getFileURLFromSystemPath( pItemImpl->m_pFullPath, &pStatus->ustrLinkTargetURL );
+        oslFileError error = osl_getFileURLFromSystemPath( sFullPath.pData, &pStatus->ustrLinkTargetURL );
         if (error != osl_File_E_None)
             return error;
 
@@ -1647,7 +1654,7 @@ oslFileError SAL_CALL osl_getFileStatus(
         if ( !pItemImpl->bFullPathNormalized )
         {
             ::osl::LongPathBuffer< sal_Unicode > aBuffer( MAX_LONG_PATH );
-            sal_uInt32 nNewLen = GetCaseCorrectPathName( o3tl::toW(rtl_uString_getStr( pItemImpl->m_pFullPath )),
+            sal_uInt32 nNewLen = GetCaseCorrectPathName( o3tl::toW( sFullPath.getStr() ),
                                                          o3tl::toW( aBuffer ),
                                                          aBuffer.getBufSizeInSymbols(),
                                                          true );
@@ -1655,11 +1662,12 @@ oslFileError SAL_CALL osl_getFileStatus(
             if ( nNewLen )
             {
                 rtl_uString_newFromStr( &pItemImpl->m_pFullPath, aBuffer );
+                sFullPath = OUString( pItemImpl->m_pFullPath );
                 pItemImpl->bFullPathNormalized = TRUE;
             }
         }
 
-        oslFileError error = osl_getFileURLFromSystemPath( pItemImpl->m_pFullPath, &pStatus->ustrFileURL );
+        oslFileError error = osl_getFileURLFromSystemPath( sFullPath.pData, &pStatus->ustrFileURL );
         if (error != osl_File_E_None)
             return error;
         pStatus->uValidFields |= osl_FileStatus_Mask_FileURL;