# HG changeset patch
# User Bruno Haible <bruno@clisp.org>
# Date 1283624996 -7200
# Node ID 66184fbdcf03453c3a44ade25605f66d2a026029
# Parent  b68fa3d66e47eca632c7b1f79dd8e9f061e4b0ed
gnulib-tool: Help migration from --import to --add-import or --update.

* gnulib-tool: Emit a verbose error message when --import is used
without any module name.

diff --git a/ChangeLog b/ChangeLog
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+2010-09-04  Bruno Haible  <bruno@clisp.org>
+
+	gnulib-tool: Help migration from --import to --add-import or --update.
+	* gnulib-tool: Emit a verbose error message when --import is used
+	without any module name.
+
 2010-09-04  Bruno Haible  <bruno@clisp.org>
 
 	Update doc about gnulib-tool.
diff --git a/gnulib-tool b/gnulib-tool
--- a/gnulib-tool
+++ b/gnulib-tool
@@ -1235,6 +1235,19 @@
       func_exit 1
     fi
   fi
+  # This code helps migrating from --import to --add-import or --update. It can
+  # be removed on 2012-01-01.
+  if test "$mode" = import && test $# = 0; then
+    echo "gnulib-tool: cowardly refusing to erase the module list." 1>&2
+    echo "The meaning of the option '--import' has changed." 1>&2
+    echo "See the documentation at" 1>&2
+    echo "<http://www.gnu.org/software/gnulib/manual/html_node/Modified-imports.html>." 1>&2
+    echo "For updating to a newer version of gnulib, use" 1>&2
+    echo "  gnulib-tool --add-import" 1>&2
+    echo "For restoring files that were omitted from version control, use" 1>&2
+    echo "  gnulib-tool --update" 1>&2
+    func_exit 1
+  fi
   if test "$mode" = update; then
     if test $# != 0; then
       echo "gnulib-tool: too many arguments in 'update' mode" 1>&2