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

@@ -121,30 +121,36 @@
 #endif
 
 
 extern "C" {
 
-static BOOL initShellProcs()
+static BOOL initShellProcs(char*& cause)
 {
     static HMODULE libShell32 = NULL;
     static HMODULE libUser32 = NULL;
     static HMODULE libComCtl32 = NULL;
     // If already initialized, return TRUE
     if (libShell32 != NULL && libUser32 != NULL) {
         return TRUE;
     }
     // Load libraries
-    libShell32 = JDK_LoadSystemLibrary("shell32.dll");
+    char *name = "shell32.dll";
+    libShell32 = JDK_LoadSystemLibrary(name);
     if (libShell32 == NULL) {
+        cause = name;
         return FALSE;
     }
-    libUser32 = JDK_LoadSystemLibrary("user32.dll");
+    name = "user32.dll";
+    libUser32 = JDK_LoadSystemLibrary(name);
     if (libUser32 == NULL) {
+        cause = name;
         return FALSE;
     }
-    libComCtl32 = JDK_LoadSystemLibrary("comctl32.dll");
+    name = "comctl32.dll";
+    libComCtl32 = JDK_LoadSystemLibrary(name);
     if (libComCtl32 == NULL) {
+        cause = name;
         return FALSE;
     }
 
     // Set up procs - libComCtl32
     fn_ImageList_GetIcon = (ImageList_GetIconType)GetProcAddress(libComCtl32, "ImageList_GetIcon");

@@ -225,12 +231,22 @@
  * Signature: ()V
  */
 JNIEXPORT void JNICALL Java_sun_awt_shell_Win32ShellFolder2_initIDs
     (JNIEnv* env, jclass cls)
 {
-    if (!initShellProcs()) {
-        JNU_ThrowInternalError(env, "Could not initialize shell library");
+    char *cause = NULL;
+    if (!initShellProcs(cause)) {
+        char msg[2048] = "Could not initialize shell library ";
+        if (cause) {
+            strcat(msg + strlen(msg), cause);
+        }
+        if (::GetLastError()) {
+            strcat(msg + strlen(msg), ". ");
+            size_t n = getLastErrorString(msg + strlen(msg), sizeof(msg) -
+                                                                   strlen(msg));
+        }
+        JNU_ThrowInternalError(env, msg);
         return;
     }
     MID_pIShellFolder = env->GetMethodID(cls, "setIShellFolder", "(J)V");
     CHECK_NULL(MID_pIShellFolder);
     FID_pIShellIcon = env->GetFieldID(cls, "pIShellIcon", "J");