Check that at least one drive is defined on startup

[Mike Hearn]

Mike Hearn <mh at codeweavers.com>
Add a check to process_init() to ensure at least one drive is defined,
as things break if that isn't the case.

Generated from:
* mike at navi.cx--2004/wine--mainline--0.9--patch-22

--- orig/dlls/kernel/process.c
+++ mod/dlls/kernel/process.c
@@ -832,6 +832,56 @@
     TRACE_(file)( "SystemDir  = %s\n", debugstr_w(DIR_System) );
 }
 
+/***********************************************************************
+ *           check_drive_config
+ *
+ * Perform a sanity check on the users drives configuration. 
+ */
+static BOOL check_drive_config()
+{
+    HKEY key;
+    char buffer[256];
+    KEY_FULL_INFORMATION *info = (KEY_FULL_INFORMATION *)buffer;
+    OBJECT_ATTRIBUTES attr;
+    DWORD total_size;
+    
+    static const WCHAR drivesW[] = {'M','a','c','h','i','n','e','\\',
+                                    'S','o','f','t','w','a','r','e','\\',
+                                    'W','i','n','e','\\',
+                                    'D','r','i','v','e','s', 0};
+    UNICODE_STRING drives;
+
+    RtlInitUnicodeString( &drives, drivesW );
+    
+    attr.Length = sizeof(attr);
+    attr.RootDirectory = 0;
+    attr.ObjectName = &drives;
+    attr.Attributes = 0;
+    attr.SecurityDescriptor = NULL;
+    attr.SecurityQualityOfService = NULL;
+    
+    if (NtOpenKey( &key, KEY_ALL_ACCESS, &attr ) != STATUS_SUCCESS) {
+        MESSAGE("wine: no [HKEY_LOCAL_MACHINE\\Software\\Wine\\Drives] key. Wine has not been configured correctly.\n");
+        return FALSE;
+    }
+
+    ZeroMemory( buffer, sizeof(buffer) );
+    if (NtQueryKey( key, KeyFullInformation, buffer, sizeof(buffer), &total_size ) != STATUS_SUCCESS) {
+        ERR("Could not query Drives key\n");
+        NtClose( key );
+        return FALSE;
+    }
+
+    if (!info->SubKeys) {
+        MESSAGE("wine: no drives are defined in the registry. Please define drive C in system.reg and then try again.\n");
+        NtClose( key );
+        return FALSE;
+    }
+
+    NtClose( key );
+    return TRUE;
+}
+    
 
 /***********************************************************************
  *           process_init
@@ -935,6 +985,9 @@
     /* registry initialisation */
     SHELL_LoadRegistry();
 
+    /* perform quick sanity check on drive configuration */
+    if (!check_drive_config()) return FALSE;
+    
     /* global boot finished, the rest is process-local */
     SERVER_START_REQ( boot_done )
     {