add syntax check for po files (multiline-strings, TGIs)

Author: memo33

.github/workflows/scala.yml

@@ -34,5 +34,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
     - uses: actions/checkout@v3
+    - name: Check PO/POT syntax
+      run: sh src/scripts/syntax-check-po.sh
     - name: Check RUL2 syntax
       run: sh src/scripts/syntax-check-rul2.sh

src/scripts/syntax-check-po.sh

@@ -0,0 +1,46 @@
+#!/bin/bash
+#
+# This script checks all the po/pot files for correct multi-line format and uppercased TGIs.
+# If any issues are found, they are printed to stdout and the script exits with a non-zero return code.
+set -e
+
+INDIR="./ltext"
+OUT="./syntax-check-po.log"
+
+sorted_input_files() {
+    find -L "$INDIR" -type f \( -name '*.po' -o -name '*.pot' \) -print0 | sort -z
+}
+
+strip_comments_and_whitespace() {
+    ${1:+ xargs -0} sed -e 's/^#.*//' -e 's/\s\+$//g' -e '/^\s*$/d'
+}
+# Note that we used sed and tail for concatenation which handle missing
+# newlines at the end of input files gracefully (unlike cat).
+
+strip_valid_po() {
+    # TGIs must be upper-case.
+    ID="[0-9A-F]\{8\}"
+    # Every line of a multi-line string should start and end with quotes.
+    QUOTEDTEXT='".*"'
+    sed -e "/^msgctxt\s\+\"$ID-$ID-$ID\"$/d" \
+        -e "/^msgid\s\+$QUOTEDTEXT$/d" \
+        -e "/^msgstr\s\+$QUOTEDTEXT$/d" \
+        -e "/^msgstr\s\+$QUOTEDTEXT$/d" \
+        -e "/^$QUOTEDTEXT$/d"
+}
+
+echo "Checking .po file syntax..."
+
+sorted_input_files | strip_comments_and_whitespace -0 | strip_valid_po > "$OUT"
+
+if [ -s "$OUT" ]; then
+    # the log file is not-empty
+    echo "Syntax errors in .po files (use uppercase TGIs and quotes on every line of text):"
+    cat "$OUT"
+    rm -f "$OUT"
+    exit 1
+else
+    echo "No syntax errors found."
+    rm -f "$OUT"
+    exit 0
+fi

src/scripts/syntax-check-rul2.sh

@@ -21,7 +21,7 @@ strip_drive_side() {
 # newlines at the end of input files gracefully (unlike cat).
 
 strip_comments_and_whitespace() {
-    sed -e "s/;.*//" -e "s/\s\+//g" -e '/^\s*$/d'
+    sed -e 's/;.*//' -e 's/\s\+//g' -e '/^\s*$/d'
 }
 
 strip_valid_rul2() {