[libxml2] Build Autotools CI tests out of source tree (VPATH)

[Nick Wellnhofer <nwellnhof src gnome org>]

commit 65b01647bf90019bea271eb0a217cf4365c20af6
Author: Nick Wellnhofer <wellnhofer aevum de>
Date:   Thu Apr 21 06:27:33 2022 +0200

    Build Autotools CI tests out of source tree (VPATH)

 .gitlab-ci.yml | 5 ++++-
 autogen.sh     | 7 +++----
 2 files changed, 7 insertions(+), 5 deletions(-)
---
diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index bb3c3723..db987a7b 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -20,8 +20,11 @@
     BASE_CONFIG: "--with-ftp --with-legacy --with-xptr-locs"
   script:
     - |
+      rm -rf build
+      mkdir build
+      cd build
       ln -s /tests/xmlconf
-      sh autogen.sh $BASE_CONFIG $CONFIG
+      sh ../autogen.sh $BASE_CONFIG $CONFIG
       make -j$(nproc) V=1 CFLAGS="$CFLAGS -Werror"
       make CFLAGS="$CFLAGS -Werror" check
 
diff --git a/autogen.sh b/autogen.sh
index 3778be71..48152631 100755
--- a/autogen.sh
+++ b/autogen.sh
@@ -1,11 +1,10 @@
 #!/bin/sh
 # Run this to generate all the initial makefiles, etc.
 
-srcdir=`dirname $0`
-test -z "$srcdir" && srcdir=. 
-
 THEDIR=`pwd`
-cd $srcdir
+cd `dirname $0`
+srcdir=`pwd`
+
 DIE=0
 
 (autoconf --version) < /dev/null > /dev/null 2>&1 || {