travis-ci: record and skip successfully built trees

diff --git a/ci/test-documentation.sh b/ci/test-documentation.sh
index 6214e6acb4a1acbc3eef764a8c610a5f6e100ee0..3d62e6c9539b04f1601b92617a514c1a8b63fe56 100755 (executable)
--- a/ci/test-documentation.sh
+++ b/ci/test-documentation.sh
@@ -3,7 +3,9 @@
 # Perform sanity checks on documentation and build it.
 #
 
-set -e
+. ${0%/*}/lib-travisci.sh
+
+gem install asciidoctor
 
 make check-builtins
 make check-docs
@@ -23,3 +25,5 @@ sed '/^GIT_VERSION = / d' stderr.log
 ! test -s stderr.log
 test -s Documentation/git.html
 grep '<meta name="generator" content="Asciidoctor ' Documentation/git.html
+
+save_good_tree