lupdate: Do not touch a translated file without target language

[ChangeLog][lupdate] lupdate will now generate an error if it is asked
to update a .ts file with translations, but without a target language.
This is to ensure that plural translations are not destroyed.

Fixes: QTBUG-53775
Change-Id: I646c1f2ec42a32dbc1a4676ad784887613607b78
Reviewed-by: Kai Koehne <kai.koehne@qt.io>

21 files changed, 114 insertions, 14 deletions

diff --git a/src/linguist/lupdate/main.cpp b/src/linguist/lupdate/main.cpp
index 134eab336..ba1126aa7 100644
--- a/src/linguist/lupdate/main.cpp
+++ b/src/linguist/lupdate/main.cpp
@@ -310,6 +310,19 @@ static void updateTsFiles(const Translator &fetchedTor, const QStringList &tsFil
                 printErr(LU::tr("lupdate warning: Specified source language '%1' disagrees with"
                                 " existing file's language '%2'. Ignoring.\n")
                          .arg(sourceLanguage, tor.sourceLanguageCode()));
+            // If there is translation in the file, the language should be recognized
+            // (when the language is not recognized, plural translations are lost)
+            if (tor.translationsExist()) {
+                QLocale::Language l;
+                QLocale::Country c;
+                tor.languageAndCountry(tor.languageCode(), &l, &c);
+                QStringList forms;
+                if (!getNumerusInfo(l, c, 0, &forms, 0)) {
+                    printErr(LU::tr("File %1 won't be updated: it contains translation but the"
+                    " target language is not recognized\n").arg(fileName));
+                    continue;
+                }
+            }
         } else {
             if (!targetLanguage.isEmpty())
                 tor.setLanguageCode(targetLanguage);
diff --git a/src/linguist/shared/translator.cpp b/src/linguist/shared/translator.cpp
index af669e235..db28ea396 100644
--- a/src/linguist/shared/translator.cpp
+++ b/src/linguist/shared/translator.cpp
@@ -433,6 +433,17 @@ void Translator::stripUntranslatedMessages()
     m_indexOk = false;
 }
 
+bool Translator::translationsExist()
+{
+    for (TMM::Iterator it = m_messages.begin(); it != m_messages.end(); ) {
+        if (it->isTranslated())
+            return true;
+        else
+            ++it;
+    }
+    return false;
+}
+
 void Translator::stripEmptyContexts()
 {
     for (TMM::Iterator it = m_messages.begin(); it != m_messages.end();)
diff --git a/src/linguist/shared/translator.h b/src/linguist/shared/translator.h
index 8919a13df..5b5d12250 100644
--- a/src/linguist/shared/translator.h
+++ b/src/linguist/shared/translator.h
@@ -135,6 +135,7 @@ public:
     void dropTranslations();
     void dropUiLines();
     void makeFileNamesAbsolute(const QDir &originalPath);
+    bool translationsExist();
 
     struct Duplicates { QSet<int> byId, byContents; };
     Duplicates resolveDuplicates();
diff --git a/tests/auto/linguist/lupdate/testdata/good/heuristics/project.ts.before b/tests/auto/linguist/lupdate/testdata/good/heuristics/project.ts.before
index ce8281033..e72debed9 100644
--- a/tests/auto/linguist/lupdate/testdata/good/heuristics/project.ts.before
+++ b/tests/auto/linguist/lupdate/testdata/good/heuristics/project.ts.before
@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="utf-8"?>
 <!DOCTYPE TS>
-<TS version="2.0">
+<TS version="2.0" language="de_DE">
 <context>
     <name>A</name>
     <message>
diff --git a/tests/auto/linguist/lupdate/testdata/good/heuristics/project.ts.result b/tests/auto/linguist/lupdate/testdata/good/heuristics/project.ts.result
index 155967a52..351bdff7d 100644
--- a/tests/auto/linguist/lupdate/testdata/good/heuristics/project.ts.result
+++ b/tests/auto/linguist/lupdate/testdata/good/heuristics/project.ts.result
@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="utf-8"?>
 <!DOCTYPE TS>
-<TS version="2.1">
+<TS version="2.1" language="de_DE">
 <context>
     <name>A</name>
     <message>
diff --git a/tests/auto/linguist/lupdate/testdata/good/merge_whitespace/project.ts.before b/tests/auto/linguist/lupdate/testdata/good/merge_whitespace/project.ts.before
index 0f84fedb8..ab91cac9d 100644
--- a/tests/auto/linguist/lupdate/testdata/good/merge_whitespace/project.ts.before
+++ b/tests/auto/linguist/lupdate/testdata/good/merge_whitespace/project.ts.before
@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="utf-8"?>
-<!DOCTYPE TS><TS version="1.1">
+<!DOCTYPE TS><TS version="1.1"  language="en_EN">
 <context>
     <name>QObject</name>
     <message>
diff --git a/tests/auto/linguist/lupdate/testdata/good/merge_whitespace/project.ts.result b/tests/auto/linguist/lupdate/testdata/good/merge_whitespace/project.ts.result
index 64ec91076..93bd54bb9 100644
--- a/tests/auto/linguist/lupdate/testdata/good/merge_whitespace/project.ts.result
+++ b/tests/auto/linguist/lupdate/testdata/good/merge_whitespace/project.ts.result
@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="utf-8"?>
 <!DOCTYPE TS>
-<TS version="2.1">
+<TS version="2.1" language="en_EN">
 <context>
     <name>QObject</name>
     <message>
diff --git a/tests/auto/linguist/lupdate/testdata/good/mergecpp_noobsolete/project.ts.before b/tests/auto/linguist/lupdate/testdata/good/mergecpp_noobsolete/project.ts.before
index feab1694d..f9915e9ba 100644
--- a/tests/auto/linguist/lupdate/testdata/good/mergecpp_noobsolete/project.ts.before
+++ b/tests/auto/linguist/lupdate/testdata/good/mergecpp_noobsolete/project.ts.before
@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="utf-8"?>
-<!DOCTYPE TS><TS version="1.1">
+<!DOCTYPE TS><TS version="1.1" language="en_EN">
 <context>
     <name></name>
     <message id="keep_id">
diff --git a/tests/auto/linguist/lupdate/testdata/good/mergecpp_noobsolete/project.ts.result b/tests/auto/linguist/lupdate/testdata/good/mergecpp_noobsolete/project.ts.result
index a0cdda96a..516072d5e 100644
--- a/tests/auto/linguist/lupdate/testdata/good/mergecpp_noobsolete/project.ts.result
+++ b/tests/auto/linguist/lupdate/testdata/good/mergecpp_noobsolete/project.ts.result
@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="utf-8"?>
 <!DOCTYPE TS>
-<TS version="2.1">
+<TS version="2.1" language="en_EN">
 <context>
     <name></name>
     <message id="keep_id">
diff --git a/tests/auto/linguist/lupdate/testdata/good/mergecpp_obsolete/project.ts.before b/tests/auto/linguist/lupdate/testdata/good/mergecpp_obsolete/project.ts.before
index 2af303be4..99443bbad 100644
--- a/tests/auto/linguist/lupdate/testdata/good/mergecpp_obsolete/project.ts.before
+++ b/tests/auto/linguist/lupdate/testdata/good/mergecpp_obsolete/project.ts.before
@@ -1,5 +1,5 @@
 <?xml version="1.0"?>
-<!DOCTYPE TS><TS version="1.1">
+<!DOCTYPE TS><TS version="1.1" language="en_EN">
 <context>
     <name></name>
     <message id="keep_id">
diff --git a/tests/auto/linguist/lupdate/testdata/good/mergecpp_obsolete/project.ts.result b/tests/auto/linguist/lupdate/testdata/good/mergecpp_obsolete/project.ts.result
index 1fcfea4e5..b6d47c8dd 100644
--- a/tests/auto/linguist/lupdate/testdata/good/mergecpp_obsolete/project.ts.result
+++ b/tests/auto/linguist/lupdate/testdata/good/mergecpp_obsolete/project.ts.result
@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="utf-8"?>
 <!DOCTYPE TS>
-<TS version="2.1">
+<TS version="2.1" language="en_EN">
 <context>
     <name></name>
     <message id="keep_id">
diff --git a/tests/auto/linguist/lupdate/testdata/good/mergeui/project.ts.before b/tests/auto/linguist/lupdate/testdata/good/mergeui/project.ts.before
index b96cd4ee9..b9333c9dd 100644
--- a/tests/auto/linguist/lupdate/testdata/good/mergeui/project.ts.before
+++ b/tests/auto/linguist/lupdate/testdata/good/mergeui/project.ts.before
@@ -1,5 +1,5 @@
 <?xml version="1.0"?>
-<!DOCTYPE TS><TS version="1.1">
+<!DOCTYPE TS><TS version="1.1" language="no_NO">
 <context>
     <name>FindDialog</name>
     <message>
diff --git a/tests/auto/linguist/lupdate/testdata/good/mergeui/project.ts.result b/tests/auto/linguist/lupdate/testdata/good/mergeui/project.ts.result
index 00c70ed94..8d51b197d 100644
--- a/tests/auto/linguist/lupdate/testdata/good/mergeui/project.ts.result
+++ b/tests/auto/linguist/lupdate/testdata/good/mergeui/project.ts.result
@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="utf-8"?>
 <!DOCTYPE TS>
-<TS version="2.1">
+<TS version="2.1" language="no_NO">
 <context>
     <name>FindDialog</name>
     <message>
diff --git a/tests/auto/linguist/lupdate/testdata/good/mergeui_obsolete/project.ts.before b/tests/auto/linguist/lupdate/testdata/good/mergeui_obsolete/project.ts.before
index f06c22ca8..d47409c84 100644
--- a/tests/auto/linguist/lupdate/testdata/good/mergeui_obsolete/project.ts.before
+++ b/tests/auto/linguist/lupdate/testdata/good/mergeui_obsolete/project.ts.before
@@ -1,5 +1,5 @@
 <?xml version="1.0"?>
-<!DOCTYPE TS><TS version="1.1">
+<!DOCTYPE TS><TS version="1.1" language="no_NO">
 <context>
     <name>FindDialog</name>
     <message>
diff --git a/tests/auto/linguist/lupdate/testdata/good/mergeui_obsolete/project.ts.result b/tests/auto/linguist/lupdate/testdata/good/mergeui_obsolete/project.ts.result
index 2636ae075..79a6e8c51 100644
--- a/tests/auto/linguist/lupdate/testdata/good/mergeui_obsolete/project.ts.result
+++ b/tests/auto/linguist/lupdate/testdata/good/mergeui_obsolete/project.ts.result
@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="utf-8"?>
 <!DOCTYPE TS>
-<TS version="2.1">
+<TS version="2.1" language="no_NO">
 <context>
     <name>FindDialog</name>
     <message>
diff --git a/tests/auto/linguist/lupdate/testdata/good/notargetlanguage/main.cpp b/tests/auto/linguist/lupdate/testdata/good/notargetlanguage/main.cpp
new file mode 100644
index 000000000..157979b70
--- /dev/null
+++ b/tests/auto/linguist/lupdate/testdata/good/notargetlanguage/main.cpp
@@ -0,0 +1,42 @@
+/****************************************************************************
+**
+** Copyright (C) 2016 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the test suite of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:GPL-EXCEPT$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 3 as published by the Free Software
+** Foundation with exceptions as appearing in the file LICENSE.GPL3-EXCEPT
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+#include <QApplication>
+#include <QPushButton>
+#include <QTranslator>
+
+int main(int argc, char *argv[])
+{
+    QApplication app(argc, argv);
+
+    QTranslator translator;
+    app.installTranslator(&translator);
+
+    QObject::tr("un mot","toto",1);
+
+    return app.exec();
+}
diff --git a/tests/auto/linguist/lupdate/testdata/good/notargetlanguage/project.pro b/tests/auto/linguist/lupdate/testdata/good/notargetlanguage/project.pro
new file mode 100644
index 000000000..759bea068
--- /dev/null
+++ b/tests/auto/linguist/lupdate/testdata/good/notargetlanguage/project.pro
@@ -0,0 +1,3 @@
+SOURCES = main.cpp
+
+TRANSLATIONS = project.ts
diff --git a/tests/auto/linguist/lupdate/testdata/good/notargetlanguage/project.ts.before b/tests/auto/linguist/lupdate/testdata/good/notargetlanguage/project.ts.before
new file mode 100644
index 000000000..7216e069c
--- /dev/null
+++ b/tests/auto/linguist/lupdate/testdata/good/notargetlanguage/project.ts.before
@@ -0,0 +1,15 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!DOCTYPE TS>
+<TS version="2.1">
+<context>
+    <name>QObject</name>
+    <message numerus="yes">
+        <location filename="main.cpp" line="39"/>
+        <source>un mot</source>
+        <comment>toto</comment>
+        <translation type="unfinished">
+            <numerusform>ein Wort</numerusform>
+        </translation>
+    </message>
+</context>
+</TS>
diff --git a/tests/auto/linguist/lupdate/testdata/good/notargetlanguage/project.ts.result b/tests/auto/linguist/lupdate/testdata/good/notargetlanguage/project.ts.result
new file mode 100644
index 000000000..7216e069c
--- /dev/null
+++ b/tests/auto/linguist/lupdate/testdata/good/notargetlanguage/project.ts.result
@@ -0,0 +1,15 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!DOCTYPE TS>
+<TS version="2.1">
+<context>
+    <name>QObject</name>
+    <message numerus="yes">
+        <location filename="main.cpp" line="39"/>
+        <source>un mot</source>
+        <comment>toto</comment>
+        <translation type="unfinished">
+            <numerusform>ein Wort</numerusform>
+        </translation>
+    </message>
+</context>
+</TS>
diff --git a/tests/auto/linguist/lupdate/testdata/good/textsimilarity/project.ts.before b/tests/auto/linguist/lupdate/testdata/good/textsimilarity/project.ts.before
index f06c22ca8..d47409c84 100644
--- a/tests/auto/linguist/lupdate/testdata/good/textsimilarity/project.ts.before
+++ b/tests/auto/linguist/lupdate/testdata/good/textsimilarity/project.ts.before
@@ -1,5 +1,5 @@
 <?xml version="1.0"?>
-<!DOCTYPE TS><TS version="1.1">
+<!DOCTYPE TS><TS version="1.1" language="no_NO">
 <context>
     <name>FindDialog</name>
     <message>
diff --git a/tests/auto/linguist/lupdate/testdata/good/textsimilarity/project.ts.result b/tests/auto/linguist/lupdate/testdata/good/textsimilarity/project.ts.result
index 2636ae075..79a6e8c51 100644
--- a/tests/auto/linguist/lupdate/testdata/good/textsimilarity/project.ts.result
+++ b/tests/auto/linguist/lupdate/testdata/good/textsimilarity/project.ts.result
@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="utf-8"?>
 <!DOCTYPE TS>
-<TS version="2.1">
+<TS version="2.1" language="no_NO">
 <context>
     <name>FindDialog</name>
     <message>