From 98d4f771c21c6b05d154cfa12830eea32bb103a3 Mon Sep 17 00:00:00 2001
From: Bill Somerville <bill@classdesign.com>
Date: Fri, 7 May 2021 01:14:51 +0100
Subject: [PATCH] Report failed sub-process exit statuses then exit gracefully

---
 map65/mainwindow.cpp | 52 +++++++++++++++++++++++++++++---------------
 map65/mainwindow.h   |  5 +++--
 2 files changed, 38 insertions(+), 19 deletions(-)

diff --git a/map65/mainwindow.cpp b/map65/mainwindow.cpp
index 1ea278965..04edfa0c2 100644
--- a/map65/mainwindow.cpp
+++ b/map65/mainwindow.cpp
@@ -1,6 +1,7 @@
 //------------------------------------------------------------------ MainWindow
 #include "mainwindow.h"
 #include "revision_utils.hpp"
+#include "widgets/MessageBox.hpp"
 #include "ui_mainwindow.h"
 #include "devsetup.h"
 #include "plotter.h"
@@ -101,14 +102,15 @@ MainWindow::MainWindow(QWidget *parent) :
           SLOT(showStatusMessage(QString)));
   createStatusBar();
 
-  connect(&proc_m65, SIGNAL(readyReadStandardOutput()),
-                    this, SLOT(readFromStdout()));
-
-  connect(&proc_m65, SIGNAL(error(QProcess::ProcessError)),
-          this, SLOT(m65_error()));
-
-  connect(&proc_m65, SIGNAL(readyReadStandardError()),
-          this, SLOT(readFromStderr()));
+  connect(&proc_m65, SIGNAL(readyReadStandardOutput()), this, SLOT(readFromStdout()));
+  connect(&proc_m65, &QProcess::errorOccurred, this, &MainWindow::m65_error);
+  connect(&proc_m65, static_cast<void (QProcess::*) (int, QProcess::ExitStatus)> (&QProcess::finished),
+          [this] (int exitCode, QProcess::ExitStatus status) {
+            if (subProcessFailed (&proc_m65, exitCode, status))
+              {
+                QTimer::singleShot (0, this, SLOT (close ()));
+              }
+          });
 
   connect(&proc_editor, SIGNAL(error(QProcess::ProcessError)),
           this, SLOT(editor_error()));
@@ -1341,11 +1343,33 @@ void MainWindow::decode()                                       //decode()
   decodeBusy(true);
 }
 
-void MainWindow::m65_error()                                     //m65_error
+bool MainWindow::subProcessFailed (QProcess * process, int exit_code, QProcess::ExitStatus status)
+{
+  if (exit_code || QProcess::NormalExit != status)
+    {
+      QStringList arguments;
+      for (auto argument: process->arguments ())
+        {
+          if (argument.contains (' ')) argument = '"' + argument + '"';
+          arguments << argument;
+        }
+      MessageBox::critical_message (this, tr ("Subprocess Error")
+                                    , tr ("Subprocess failed with exit code %1")
+                                    .arg (exit_code)
+                                    , tr ("Running: %1\n%2")
+                                    .arg (process->program () + ' ' + arguments.join (' '))
+                                    .arg (QString {process->readAllStandardError()}));
+      return true;
+    }
+  return false;
+}
+
+void MainWindow::m65_error (QProcess::ProcessError)
 {
   if(!m_killAll) {
-    msgBox("Error starting or running\n" + m_appDir + "/m65 -s");
-    exit(1);
+    msgBox("Error starting or running\n" + m_appDir + "/m65 -s\n\n"
+           + proc_m65.errorString ());
+    QTimer::singleShot (0, this, SLOT (close ()));
   }
 }
 
@@ -1356,12 +1380,6 @@ void MainWindow::editor_error()                                 //editor_error
   }
 }
 
-void MainWindow::readFromStderr()                             //readFromStderr
-{
-  QByteArray t=proc_m65.readAllStandardError();
-  msgBox(t);
-}
-
 void MainWindow::readFromStdout()                             //readFromStdout
 {
   while(proc_m65.canReadLine())
diff --git a/map65/mainwindow.h b/map65/mainwindow.h
index 862623f45..a93a9431a 100644
--- a/map65/mainwindow.h
+++ b/map65/mainwindow.h
@@ -6,6 +6,7 @@
 #include <QTimer>
 #include <QDateTime>
 #include <QHash>
+#include <QProcess>
 #include "getfile.h"
 #include "soundin.h"
 #include "soundout.h"
@@ -39,8 +40,7 @@ public slots:
   void diskWriteFinished();
   void freezeDecode(int n);
   void readFromStdout();
-  void readFromStderr();
-  void m65_error();
+  void m65_error (QProcess::ProcessError);
   void editor_error();
   void guiUpdate();
   void doubleClickOnCall(QString hiscall, bool ctrl);
@@ -277,6 +277,7 @@ private:
     void ba2msg(QByteArray ba, char* message);
     void msgtype(QString t, QLineEdit* tx);
     void stub();
+  bool subProcessFailed (QProcess *, int exit_code, QProcess::ExitStatus);
 };
 
 extern void getfile(QString fname, bool xpol, int idInt);