lib/fetcher: Allow clients to append to User-Agent

We do already have `http-headers`, which potentially could be used to
allow clients to completely override the field, but it seems like the
more common use case is simply to append.

Closes: #1496
Approved by: cgwalters

tests/libtest.sh

@@ -234,10 +234,9 @@ ostree_repo_init() {
 # The original one; use setup_fake_remote_repo2 for newer code,
 # down the line we'll try to port tests.
 setup_fake_remote_repo1() {
-    mode=$1
-    commit_opts=${2:-}
-    args=${3:-}
-    shift
+    mode=$1; shift
+    commit_opts=${1:-}
+    [ $# -eq 0 ] || shift
     oldpwd=`pwd`
     mkdir ostree-srv
     cd ostree-srv
@@ -263,7 +262,7 @@ setup_fake_remote_repo1() {
     mkdir ${test_tmpdir}/httpd
     cd httpd
     ln -s ${test_tmpdir}/ostree-srv ostree
-    ${OSTREE_HTTPD} --autoexit --log-file $(pwd)/httpd.log --daemonize -p ${test_tmpdir}/httpd-port $args
+    ${OSTREE_HTTPD} --autoexit --log-file $(pwd)/httpd.log --daemonize -p ${test_tmpdir}/httpd-port "$@"
     port=$(cat ${test_tmpdir}/httpd-port)
     echo "http://127.0.0.1:${port}" > ${test_tmpdir}/httpd-address
     cd ${oldpwd} 

tests/test-remote-cookies.sh

@@ -27,7 +27,8 @@ echo '1..4'
 . $(dirname $0)/libtest.sh
 
 setup_fake_remote_repo1 "archive" "" \
-  "--expected-cookies foo=bar --expected-cookies baz=badger"
+  --expected-cookies foo=bar \
+  --expected-cookies baz=badger
 
 assert_fail (){ 
   if $@; then

tests/test-remote-headers.sh

@@ -25,8 +25,13 @@ echo '1..2'
 
 . $(dirname $0)/libtest.sh
 
+V=$($CMD_PREFIX ostree --version | \
+  python3 -c 'import sys, yaml; print(yaml.safe_load(sys.stdin)["libostree"]["Version"])')
+
 setup_fake_remote_repo1 "archive" "" \
-  "--expected-header foo=bar --expected-header baz=badger"
+  --expected-header foo=bar \
+  --expected-header baz=badger \
+  --expected-header "User-Agent=libostree/$V dodo/2.15"
 
 assert_fail (){
   set +e
@@ -46,9 +51,22 @@ ${CMD_PREFIX} ostree --repo=repo remote add --set=gpg-verify=false origin $(cat
 # Sanity check the setup, without headers the pull should fail
 assert_fail ${CMD_PREFIX} ostree --repo=repo pull origin main
 
+# without proper User-Agent, the pull should fail
+assert_fail ${CMD_PREFIX} ostree --repo=repo pull origin main \
+  --http-header foo=bar \
+  --http-header baz=badger
+assert_fail ${CMD_PREFIX} ostree --repo=repo pull origin main \
+  --http-header foo=bar \
+  --http-header baz=badger \
+  --append-user-agent bar/1.2
+
 echo "ok setup done"
 
 # Now pull should succeed now
-${CMD_PREFIX} ostree --repo=repo pull --http-header foo=bar --http-header baz=badger origin main
+${CMD_PREFIX} ostree --repo=repo pull \
+  --http-header foo=bar \
+  --http-header baz=badger \
+  --append-user-agent dodo/2.15 \
+  origin main
 
 echo "ok pull succeeded"