Use TIOCSWINSZ ioctl to set pty's pixel size, so it will be reported to apps using TIOCGWINSZE

src/Pty.cpp

@@ -11,6 +11,9 @@
 
 // System
 #include <csignal>
+#if !defined(Q_OS_WIN)
+#include <sys/ioctl.h> //ioctl() and TIOCSWINSZ
+#endif
 #include <termios.h>
 
 // Qt
@@ -85,9 +88,23 @@ void Pty::setWindowSize(int columns, int lines)
 
     if (pty()->masterFd() >= 0) {
         pty()->setWinSize(lines, columns);
+#if !defined(Q_OS_WIN)
+        struct winsize w;
+        w.ws_xpixel = _windowWidth;
+        w.ws_ypixel = _windowHeight;
+        w.ws_col = _windowColumns;
+        w.ws_row = _windowLines;
+        ioctl(pty()->masterFd(), TIOCSWINSZ, &w);
+#endif
     }
 }
 
+void Pty::setPixelSize(int width, int height)
+{
+    _windowWidth = width;
+    _windowHeight = height;
+}
+
 QSize Pty::windowSize() const
 {
     return {_windowColumns, _windowLines};

src/Pty.h

@@ -90,6 +90,7 @@ public:
      * used by this teletype.
      */
     void setWindowSize(int columns, int lines);
+    void setPixelSize(int width, int height);
 
     /** Returns the size of the window used by this teletype.  See setWindowSize() */
     QSize windowSize() const;
@@ -163,6 +164,8 @@ private:
 
     int _windowColumns;
     int _windowLines;
+    int _windowWidth;
+    int _windowHeight;
     char _eraseChar;
     bool _xonXoff;
     bool _utf8;

src/session/Session.cpp

@@ -724,8 +724,9 @@ void Session::sessionAttributeRequest(int id, uint terminator)
     }
 }
 
-void Session::onViewSizeChange(int /*height*/, int /*width*/)
+void Session::onViewSizeChange(int height, int width)
 {
+    _shellProcess->setPixelSize(width, height);
     updateTerminalSize();
 }