[LyX/master] Fixup 9f92fc92: improve FIXME in SystemcallPrivate::startProcess

[Jean-Marc Lasgouttes]

commit 67c85f54c4d7422b715898070e63dfe7a984a6ca
Author: Jean-Marc Lasgouttes <lasgouttes at lyx.org>
Date:   Thu May 20 13:17:55 2021 +0200

    Fixup 9f92fc92: improve FIXME in SystemcallPrivate::startProcess
    
    I wanted to remove the test  Qt >= 5.15, but now I see that it is
    not possible because of QProcess::splitCommand.
    
    Neverthless, the best would be to change parsecmd.
---
 src/support/Systemcall.cpp |    8 ++++++++
 1 files changed, 8 insertions(+), 0 deletions(-)

diff --git a/src/support/Systemcall.cpp b/src/support/Systemcall.cpp
index 00adbf8..f3703b8 100644
--- a/src/support/Systemcall.cpp
+++ b/src/support/Systemcall.cpp
@@ -370,6 +370,14 @@ void SystemcallPrivate::startProcess(QString const & cmd, string const & path,
 	cmd_ = cmd;
 #if (QT_VERSION >= QT_VERSION_CHECK(5, 15, 0))
 	// FIXME pass command and arguments separated in the first place
+	/* The versions of startDetached() and start() that accept a
+	 * QStringList object exist since Qt4, but it is only in Qt 5.15
+	 * that splitCommand() was introduced and the plain versions of
+	 * start/startDetached() have been deprecated.
+	 * The cleanest solution would be to have parsecmd() produce a
+	 * QStringList for arguments, instead of transforming the string
+	 * into something that the QProcess splitter accepts.
+	*/
 	QStringList arguments = QProcess::splitCommand(toqstr(latexEnvCmdPrefix(path, lpath)) + cmd_);
 	QString command = (arguments.empty()) ? QString() : arguments.first();
 	if (arguments.size() == 1)