scripts: Add script to merge translation messages

Since the other components can be scripted, we might as well add a
wrapper script to merge new translation strings into PO files.

Author: dbnicholson

addons/block_code/README.md

@@ -99,13 +99,8 @@ up to date.
   shell script.
 
 * If the POT file has changed, the PO message files need to be updated. This
-  can be done using the gettext `msgmerge` tool in the
-  `addons/block_code/locale` directory:
-  ```
-  for po in *.po; do
-    msgmerge --update --backup=none "$po" godot_block_coding.pot
-  done
-  ```
+  can be done using the gettext `msgmerge` tool with the
+  `scripts/merge-messages.sh` shell script.
 
 [pot-generation]: https://docs.godotengine.org/en/stable/tutorials/i18n/localization_using_gettext.html#automatic-generation-using-the-editor
 

scripts/merge-messages.sh

@@ -0,0 +1,14 @@
+#!/bin/sh
+
+# Merge new strings from POT file into message catalogs.
+set -e
+
+SCRIPTDIR=$(dirname "$0")
+PROJDIR=$(dirname "$SCRIPTDIR")
+LOCALEDIR="$PROJDIR/addons/block_code/locale"
+POT="$LOCALEDIR/godot_block_coding.pot"
+
+for po in "$LOCALEDIR"/*.po; do
+    echo -n "$po"
+    msgmerge --update --backup=none "$po" "$POT"
+done