krb5 commit: Check distclean target in Travis build

https://github.com/krb5/krb5/commit/4c547e03daffe18c5477be7075e52f69f84acb08
commit 4c547e03daffe18c5477be7075e52f69f84acb08
Author: Greg Hudson <[email protected]>
Date:   Mon Jul 9 11:32:57 2018 -0400

    Check distclean target in Travis build
    
    Move the build commands to a shell script, run with the -e flag so any
    failure causes the script to exit.  In the script, verify that "make
    distclean" removes everything produced by "make" and "make check".

 .travis-ci.sh |   11 +++++++++++
 .travis.yml   |    2 +-
 2 files changed, 12 insertions(+), 1 deletions(-)

diff --git a/.travis-ci.sh b/.travis-ci.sh
new file mode 100644
index 0000000..4e6e1b6
--- /dev/null
+++ b/.travis-ci.sh
@@ -0,0 +1,11 @@
+cd src
+autoreconf
+./configure --enable-maintainer-mode --with-ldap
+make $MAKEVARS
+make check
+make distclean
+# Check for files unexpectedly not removed by make distclean.
+rm -rf autom4te.cache configure include/autoconf.h.in
+if [ -n "$(git ls-files -o)" ]; then
+  exit 1
+fi
diff --git a/.travis.yml b/.travis.yml
index eb48036..a7980d7 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -21,4 +21,4 @@ before_install:
   - sudo make install
   - cd ../..
 
-script: cd src && autoreconf && ./configure --enable-maintainer-mode --with-ldap && make $MAKEVARS && make check
+script: sh -ex .travis-ci.sh