Correct issue where too narrow a console can break help output

If the terminal width used to display the help output is narrower than
the longest defined argument, the command line parser will attempt to
wrap the help text at a negative length, and will eventually OOM.  This
makes sure that the wrap function does not allow that, and tries to
behave a bit more intelligently during help output.

Fixes #11688

mythtv/libs/libmythbase/mythcommandlineparser.cpp

@@ -259,6 +259,17 @@ QString CommandLineArg::GetHelpString(int off, QString group, bool force) const
     QString helpstr;
     QTextStream msg(&helpstr, QIODevice::WriteOnly);
     int termwidth = GetTermWidth();
+    if (termwidth < off)
+    {
+        if (off > 70)
+            // developer has configured some absurdly long command line
+            // arguments, but we still need to do something
+            termwidth = off+40;
+        else
+            // user is running uselessly narrow console, use a sane console
+            // width instead
+            termwidth = 79;
+    }
 
     if (m_help.isEmpty() && !force)
         // only print if there is a short help to print

mythtv/libs/libmythbase/mythmiscutil.cpp

@@ -943,6 +943,10 @@ void wrapList(QStringList &list, int width)
 {
     int i;
 
+    // if this is triggered, something has gone seriously wrong
+    // the result won't really be usable, but at least it won't crash
+    width = max(width, 5);
+
     for(i = 0; i < list.size(); i++)
     {
         QString string = list.at(i);