* cygtls.cc (_cygtls::remove): Eliminate compiler warning.

* dir.cc (mkdir): Check path for writability.
(rmdir): Ditto.  Remove check for special directories.
* path.cc (path_conv::check): Set PATH_RO for virtual devices.  Set error if
read-only and asked for writability.
* path.h (pathconv_arg): Add PC_WRITABLE.
(path_types): Add PATH_RO.
(path_conv::isro): Add (currently unused) check for read-only filesystem.
Return "ENOSHARE" when we know a share doesn't exist.
* include/sys/mount.h: Add MOUNT_RO flag.
* autoload.cc (WNetGetResourceInformationA): Import.
* fhandler_netdrive.cc (fhandler_netdrive::exists): Detect actual existence of
remote system rather than always assuming that it exists.

1 files changed, 12 insertions, 5 deletions

diff --git a/winsup/cygwin/path.cc b/winsup/cygwin/path.cc
index 52a04fc9f..09382daff 100644
--- a/winsup/cygwin/path.cc
+++ b/winsup/cygwin/path.cc
@@ -675,6 +675,7 @@ path_conv::check (const char *src, unsigned opt,
 		      fileattr = INVALID_FILE_ATTRIBUTES;
 		    goto virtual_component_retry;
 		}
+	      path_flags |= PATH_RO;
 	      goto out;
 	    }
 	  /* devn should not be a device.  If it is, then stop parsing now. */
@@ -881,15 +882,21 @@ virtual_component_retry:
 out:
   bool strip_tail = false;
   /* If the user wants a directory, do not return a symlink */
-  if (!need_directory || error)
-    /* nothing to do */;
-  else if (fileattr & FILE_ATTRIBUTE_DIRECTORY)
-    path_flags &= ~PATH_SYMLINK;
+  if ((opt & PC_WRITABLE) && (path_flags & PATH_RO))
+    {
+      debug_printf ("%s is on a read-only filesystem", path);
+      error = EROFS;
+      return;
+    }
   else if (isvirtual_dev (dev.devn) && fileattr == INVALID_FILE_ATTRIBUTES)
     {
-      error = ENOENT;
+      error = dev.devn == FH_NETDRIVE ? ENOSHARE : ENOENT;
       return;
     }
+  else if (!need_directory || error)
+    /* nothing to do */;
+  else if (fileattr & FILE_ATTRIBUTE_DIRECTORY)
+    path_flags &= ~PATH_SYMLINK;
   else
     {
       debug_printf ("%s is a non-directory", path);