Avoid passing NULL as memcpy source (undefined behavior)

[wimlib] / src / win32_apply.c

diff --git a/src/win32_apply.c b/src/win32_apply.c
index 9ed563bb78d7e0996bc6810bc42980f70eeedfb6..cb488a9f6ed656013b74b67cacbf74b6c63914af 100644 (file)
--- a/src/win32_apply.c
+++ b/src/win32_apply.c
@@ -901,7 +901,9 @@ build_extraction_path(const struct wim_dentry *dentry,
             d = d->d_parent)
        {
                p -= d->d_extraction_name_nchars;
-               wmemcpy(p, d->d_extraction_name, d->d_extraction_name_nchars);
+               if (d->d_extraction_name_nchars)
+                       wmemcpy(p, d->d_extraction_name,
+                               d->d_extraction_name_nchars);
                *--p = '\\';
        }
        /* No leading slash  */
@@ -1099,6 +1101,7 @@ adjust_compression_attribute(HANDLE h, const struct wim_dentry *dentry,
        FILE_BASIC_INFORMATION info;
        NTSTATUS status;
        USHORT compression_state;
+       DWORD bytes_returned;
 
        /* Get current attributes  */
        status = (*func_NtQueryInformationFile)(h, &ctx->iosb,
@@ -1118,20 +1121,14 @@ adjust_compression_attribute(HANDLE h, const struct wim_dentry *dentry,
        else
                compression_state = COMPRESSION_FORMAT_NONE;
 
-       status = (*func_NtFsControlFile)(h,
-                                        NULL,
-                                        NULL,
-                                        NULL,
-                                        &ctx->iosb,
-                                        FSCTL_SET_COMPRESSION,
-                                        &compression_state,
-                                        sizeof(USHORT),
-                                        NULL,
-                                        0);
-       if (NT_SUCCESS(status))
+       /* Note: don't use NtFsControlFile() here unless prepared to handle
+        * STATUS_PENDING.  */
+       if (DeviceIoControl(h, FSCTL_SET_COMPRESSION,
+                           &compression_state, sizeof(USHORT), NULL, 0,
+                           &bytes_returned, NULL))
                return 0;
 
-       winnt_error(status, L"Can't %s compression attribute on \"%ls\"",
+       win32_error(GetLastError(), L"Can't %s compression attribute on \"%ls\"",
                    (compressed ? "set" : "clear"), current_path(ctx));
        return WIMLIB_ERR_SET_ATTRIBUTES;
 }