win32 compilation fixes


git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@2134 c046a42c-6fe2-441c-8c8c-71466251a162
diff --git a/block.c b/block.c
index 3b35500..12fc2ef 100644
--- a/block.c
+++ b/block.c
@@ -182,11 +182,17 @@
 #endif
 
 #ifdef _WIN32
+static int is_windows_drive_prefix(const char *filename)
+{
+    return (((filename[0] >= 'a' && filename[0] <= 'z') ||
+             (filename[0] >= 'A' && filename[0] <= 'Z')) &&
+            filename[1] == ':');
+}
+    
 static int is_windows_drive(const char *filename)
 {
-    if (((filename[0] >= 'a' && filename[0] <= 'z') ||
-         (filename[0] >= 'A' && filename[0] <= 'Z')) &&
-        filename[1] == ':' && filename[2] == '\0')
+    if (is_windows_drive_prefix(filename) && 
+        filename[2] == '\0')
         return 1;
     if (strstart(filename, "\\\\.\\", NULL) ||
         strstart(filename, "//./", NULL))
@@ -203,7 +209,8 @@
     const char *p;
 
 #ifdef _WIN32
-    if (is_windows_drive(filename))
+    if (is_windows_drive(filename) ||
+        is_windows_drive_prefix(filename))
         return &bdrv_raw;
 #endif
     p = strchr(filename, ':');