8292866: Java_sun_awt_shell_Win32ShellFolder2_getLinkLocation check MultiByteToWideChar return value for failures

Reviewed-by: goetz
Backport-of: 699c42962eeaa6aa950ad86c2dd1f77316a1da3e

Author: MBaesken

src/java.desktop/windows/native/libawt/windows/ShellFolder2.cpp

@@ -700,6 +700,7 @@ JNIEXPORT jlong JNICALL Java_sun_awt_shell_Win32ShellFolder2_getLinkLocation
     STRRET strret;
     OLECHAR olePath[MAX_PATH]; // wide-char version of path name
     LPWSTR wstr;
+    int ret;
 
     IShellFolder* pParent = (IShellFolder*)parentIShellFolder;
     if (pParent == NULL) {
@@ -719,12 +720,18 @@ JNIEXPORT jlong JNICALL Java_sun_awt_shell_Win32ShellFolder2_getLinkLocation
     switch (strret.uType) {
       case STRRET_CSTR :
         // IShellFolder::ParseDisplayName requires the path name in Unicode.
-        MultiByteToWideChar(CP_ACP, MB_PRECOMPOSED, strret.cStr, -1, olePath, MAX_PATH);
+        ret = MultiByteToWideChar(CP_ACP, MB_PRECOMPOSED, strret.cStr, -1, olePath, MAX_PATH);
+        if (ret == 0) {
+            return NULL;
+        }
         wstr = olePath;
         break;
 
       case STRRET_OFFSET :
-        MultiByteToWideChar(CP_ACP, MB_PRECOMPOSED, (CHAR *)pidl + strret.uOffset, -1, olePath, MAX_PATH);
+        ret = MultiByteToWideChar(CP_ACP, MB_PRECOMPOSED, (CHAR *)pidl + strret.uOffset, -1, olePath, MAX_PATH);
+        if (ret == 0) {
+            return NULL;
+        }
         wstr = olePath;
         break;