Test translation imports

Test imported files whether those are valid (can be compiled by
gettext) and do not propose them if they are invalid.

If there are invalid files, a proposal of valid files will still happen.
The script will fail at the end so that these invalid files can be
detected.

Change-Id: Ia48181bc79903dd47be054a6f7c7ee535506d282

jenkins/scripts/common_translation_update.sh

@@ -22,6 +22,9 @@ TOPIC=zanata/translations
 # Used for setup.py babel commands
 QUIET="--quiet"
 
+# Have invalid files been found?
+INVALID_PO_FILE=0
+
 # Get a module name of a project
 function get_modulename {
     local project=$1
@@ -381,8 +384,12 @@ function setup_django_openstack_auth {
         '{locale_with_underscore}/LC_MESSAGES/django.po' -f zanata.xml
 }
 
-# Filter out files that we do not want to commit
+# Filter out files that we do not want to commit.
+# Sets global variable INVALID_PO_FILE to 1 if any invalid files are
+# found.
 function filter_commits {
+    local ret
+
     # Don't add new empty files.
     for f in $(git diff --cached --name-only --diff-filter=A); do
         # Files should have at least one non-empty msgid string.
@@ -409,6 +416,21 @@ function filter_commits {
             | egrep -v "$REGEX" \
             | egrep -c "^([+][^+#])")
         set -e
+        # Check that imported po files are valid
+        if [[ $f =~ .po$ ]] ; then
+            set +e
+            msgfmt --check-format -o /dev/null $f
+            ret=$?
+            set -e
+            if [ $ret -ne "0" ] ; then
+                # Set change to zero so that next expression reverts
+                # change of this file.
+                changed=0
+                echo "ERROR: File $f is an invalid po file."
+                echo "ERROR: The file has not been imported and needs fixing!"
+                INVALID_PO_FILE=1
+            fi
+        fi
         if [ $changed -eq 0 ]; then
             git reset -q "$f"
             git checkout -- "$f"

jenkins/scripts/propose_translation_update.sh

@@ -258,3 +258,9 @@ filter_commits
 
 # Propose patch to gerrit if there are changes.
 send_patch "$BRANCH"
+
+if [ $INVALID_PO_FILE -eq 1 ] ; then
+    echo "At least one po file in invalid. Fix all invalid files on the"
+    echo "translation server."
+    exit 1
+fi