travis: new travis_install_omf script to checkout PR

.travis.yml

@@ -22,7 +22,10 @@ before_install:
   - tests/install_fish.sh
 
 before_script: pwd; tree -h
-script: "/bin/sh bin/install"
+
+script:
+  - /bin/sh tests/travis_install_omf.sh
+
 after_script:
   - cd ~/.config/fish; tree -h; find . -type f | xargs cat
 

tests/travis_install_omf.sh

+#!/bin/sh
+
+git () {
+  case $1 in
+    clone)
+      command git "$@"
+      if test "$TRAVIS_PULL_REQUEST" != "false"; then
+        echo "! detecting a pull request !"
+	echo "$ git -C $OMF_PATH fetch origin +refs/pull/$TRAVIS_PULL_REQUEST/merge:"
+	git -C $OMF_PATH fetch origin +refs/pull/$TRAVIS_PULL_REQUEST/merge:
+        echo "$ git -C $OMF_PATH checkout -qf FETCH_HEAD"
+        git -C $OMF_PATH checkout -qf FETCH_HEAD
+      fi
+      ;;
+    *)
+      command git "$@"
+      ;;
+  esac
+}
+
+. $TRAVIS_BUILD_DIR/bin/install