[LyX/master] Add message dialog to LFUN_CITATION_OPEN chain

[Juergen Spitzmueller]

commit 21955431884f1e25e5806a909243491a8b9829fb
Author: Juergen Spitzmueller <spitz at lyx.org>
Date:   Tue Aug 29 14:43:59 2023 +0200

    Add message dialog to LFUN_CITATION_OPEN chain
    
    This addresses security concerns.
---
 src/frontends/qt/GuiView.cpp    |    3 +-
 src/frontends/qt/qt_helpers.cpp |   40 ++++++++++++++++++++++++++++++++++++++-
 src/frontends/qt/qt_helpers.h   |    2 +
 3 files changed, 43 insertions(+), 2 deletions(-)

diff --git a/src/frontends/qt/GuiView.cpp b/src/frontends/qt/GuiView.cpp
index 2d8847e..273fa38 100644
--- a/src/frontends/qt/GuiView.cpp
+++ b/src/frontends/qt/GuiView.cpp
@@ -5071,12 +5071,13 @@ void GuiView::dispatch(FuncRequest const & cmd, DispatchResult & dr)
 			break;
 
 		case LFUN_CITATION_OPEN: {
+			LASSERT(doc_buffer, break);
 			string pdfv, psv;
 			if (theFormats().getFormat("pdf"))
 				pdfv = theFormats().getFormat("pdf")->viewer();
 			if (theFormats().getFormat("ps"))
 				psv = theFormats().getFormat("ps")->viewer();
-			frontend::showTarget(argument, pdfv, psv);
+			frontend::showTarget(argument, doc_buffer->absFileName(), pdfv, psv);
 			break;
 		}
 
diff --git a/src/frontends/qt/qt_helpers.cpp b/src/frontends/qt/qt_helpers.cpp
index ed2edec..230c89b 100644
--- a/src/frontends/qt/qt_helpers.cpp
+++ b/src/frontends/qt/qt_helpers.cpp
@@ -33,9 +33,12 @@
 #include <QDesktopServices>
 #include <QDir>
 #include <QLineEdit>
+#include <QMessageBox>
 #include <QLocale>
 #include <QPalette>
+#include <QPushButton>
 #include <QSet>
+#include <QSettings>
 #include <QTextLayout>
 #include <QTextDocument>
 #include <QToolTip>
@@ -292,9 +295,44 @@ void showDirectory(FileName const & directory)
 				qstring_to_ucs4(qurl.toString())));
 }
 
-void showTarget(string const & target, string const & pdfv, string const & psv)
+void showTarget(string const & target, string const & docpath,
+		string const & pdfv, string const & psv)
 {
 	LYXERR(Debug::INSETS, "Showtarget:" << target << "\n");
+
+	// security measure: ask user before opening if document is not marked trusted.
+	QSettings settings;
+	if (!settings.value("trusted documents/" + toqstr(docpath), false).toBool()) {
+		QCheckBox * dontShowAgainCB = new QCheckBox();
+		dontShowAgainCB->setText(qt_("&Trust this document and do not ask me again!"));
+		dontShowAgainCB->setToolTip(qt_("If you check this, LyX will open all targets without asking for the given document in the future."));
+		docstring const warn =
+			prefixIs(target, "EXTERNAL ") ?
+					bformat(_("LyX will search your directory for files with the following keywords in their name "
+						  "and then open it in an external application, if a file is found:\n"
+						  "'%1$s'\n"
+						  "Be aware that this might entail security infringements!\n"
+						  "Only do this if you trust origin of the document and the keywords used!\n"
+						  "How do you want to proceed?"), from_utf8(target).substr(9, docstring::npos))
+				      : bformat(_("LyX wants to open the following link in an external application:\n"
+						  "%1$s\n"
+						  "Be aware that this might entail security infringements!\n"
+						  "Only do this if you trust origin of the document and the target of the link!\n"
+						  "How do you want to proceed?"), from_utf8(target));
+		QMessageBox box(QMessageBox::Warning, qt_("Open external target?"), toqstr(warn),
+				QMessageBox::NoButton, qApp->focusWidget());
+		QPushButton * openButton = box.addButton(qt_("&Open Target"), QMessageBox::ActionRole);
+		box.addButton(QMessageBox::Abort);
+		box.setCheckBox(dontShowAgainCB);
+		box.setDefaultButton(QMessageBox::Abort);
+		box.exec();
+		if (box.clickedButton() != openButton)
+			return;
+		if (dontShowAgainCB->isChecked())
+			settings.setValue("trusted documents/"
+				+ toqstr(docpath), true);
+	}
+	
 	if (prefixIs(target, "EXTERNAL ")) {
 		if (!lyxrc.citation_search)
 			return;
diff --git a/src/frontends/qt/qt_helpers.h b/src/frontends/qt/qt_helpers.h
index f3230b2..dc19aea 100644
--- a/src/frontends/qt/qt_helpers.h
+++ b/src/frontends/qt/qt_helpers.h
@@ -93,8 +93,10 @@ void setMessageColour(std::list<QWidget *> highlighted,
 void showDirectory(support::FileName const & directory);
 /// handle request for showing citation content - shows pdf/ps or
 /// web page in target; external script can be used for pdf/ps view
+/// \p docpath holds the document path,
 /// \p pdfv takes a pad viewer, \p psv a ps viewer
 void showTarget(std::string const & target,
+		std::string const & docpath,
 		std::string const & pdfv,
 		std::string const & psv);