Fix check-newsfragment for debian-only changes. (#4825)

changelog.d/4825.misc

@@ -0,0 +1 @@
+Fix check-newsfragment for debian-only changes.

scripts-dev/check-newsfragment

@@ -7,14 +7,12 @@ set -e
 
 # make sure that origin/develop is up to date
 git remote set-branches --add origin develop
-git fetch --depth=1 origin develop
-
-UPSTREAM=origin/develop
+git fetch origin develop
 
 # if there are changes in the debian directory, check that the debian changelog
 # has been updated
-if ! git diff --quiet $UPSTREAM... -- debian; then
-    if git diff --quiet $UPSTREAM... -- debian/changelog; then
+if ! git diff --quiet FETCH_HEAD... -- debian; then
+    if git diff --quiet FETCH_HEAD... -- debian/changelog; then
         echo "Updates to debian directory, but no update to the changelog." >&2
         exit 1
     fi
@@ -22,7 +20,7 @@ fi
 
 # if there are changes *outside* the debian directory, check that the
 # newsfragments have been updated.
-if git diff --name-only $UPSTREAM... | grep -qv '^develop/'; then
+if git diff --name-only FETCH_HEAD... | grep -qv '^debian/'; then
     tox -e check-newsfragment
 fi
 
@@ -31,7 +29,7 @@ echo "--------------------------"
 echo
 
 # check that any new newsfiles on this branch end with a full stop.
-for f in `git diff --name-only $UPSTREAM... -- changelog.d`; do
+for f in `git diff --name-only FETCH_HEAD... -- changelog.d`; do
     lastchar=`tr -d '\n' < $f | tail -c 1`
     if [ $lastchar != '.' ]; then
         echo -e "\e[31mERROR: newsfragment $f does not end with a '.'\e[39m" >&2