[PATCH] announce-gen: avoid perl warnings

[Assaf Gordon]

Hello,

When running "./build-aux/announce-gen" without any parameters, there are three "use 
of uninitialized value" warnings:
====
$ ./build-aux/announce-gen
announce-gen: release type not specified
announce-gen: package name not specified
announce-gen: previous version string not specified
announce-gen: current version string not specified
announce-gen: GnuPG key ID not specified
announce-gen: URL directory name(s) not specified
announce-gen: Use of uninitialized value $bootstrap_tools in split at 
./build-aux/announce-gen line 419.
announce-gen: Use of uninitialized value $release_type in exists at 
./build-aux/announce-gen line 426.
announce-gen: Use of uninitialized value $release_type in concatenation (.) or 
string at ./build-aux/announce-gen line 426.
announce-gen: '': invalid release type
Try 'announce-gen --help' for more information.
====

The attached patch avoids them.

Regards,
 -gordon

>From 0c9468d8528a31c936ed1c898bbc64d471e484cd Mon Sep 17 00:00:00 2001
From: "A. Gordon" <assafgor...@gmail.com>
Date: Wed, 9 Jul 2014 19:18:40 -0400
Subject: [PATCH] announce-gen: avoid perl warnings

* build-aux/announce-gen - add two minor checks to avoid
"use of uninitialized value" warnings when command-line parameters are
missing.
---
 build-aux/announce-gen | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/build-aux/announce-gen b/build-aux/announce-gen
index db9ed50..a3aebf7 100755
--- a/build-aux/announce-gen
+++ b/build-aux/announce-gen
@@ -416,14 +416,15 @@ sub get_tool_versions ($$)
   @url_dir_list
     or (warn "URL directory name(s) not specified\n"), $fail = 1;
 
-  my @tool_list = split ',', $bootstrap_tools;
+  my @tool_list = split ',', $bootstrap_tools
+    if $bootstrap_tools;
 
   grep (/^gnulib$/, @tool_list) ^ defined $gnulib_version
     and (warn "when specifying gnulib as a tool, you must also specify\n"
         . "--gnulib-version=V, where V is the result of running git describe\n"
         . "in the gnulib source directory.\n"), $fail = 1;
 
-  exists $valid_release_types{$release_type}
+  !$release_type || exists $valid_release_types{$release_type}
     or (warn "'$release_type': invalid release type\n"), $fail = 1;
 
   @ARGV
-- 
1.9.1