From 6fbf8c58f72ed22bfe46d42505f2eb7da4cb0866 Mon Sep 17 00:00:00 2001
From: Theo Arends <11044339+arendst@users.noreply.github.com>
Date: Sun, 15 Dec 2024 12:33:43 +0100
Subject: [PATCH] Fix GUI timing related divide by zero exception

---
 CHANGELOG.md                                  |  1 +
 .../xdrv_01_9_webserver.ino                   | 36 +++++++++----------
 .../tasmota_xdrv_driver/xdrv_13_display.ino   | 18 +++-------
 3 files changed, 24 insertions(+), 31 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index e705f0533..f2885de68 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -21,6 +21,7 @@ All notable changes to this project will be documented in this file.
 - MCP23xxx, PCF8574 and Shift595 power control when a display is configured regression from v14.3.0.7
 - Display DisplayMode adds a display device while not configured
 - GUI intermittent exception on screen updates due to flash access
+- GUI timing related divide by zero exception
 
 ### Removed
 
diff --git a/tasmota/tasmota_xdrv_driver/xdrv_01_9_webserver.ino b/tasmota/tasmota_xdrv_driver/xdrv_01_9_webserver.ino
index 5c9f55e5a..cf32f4e76 100644
--- a/tasmota/tasmota_xdrv_driver/xdrv_01_9_webserver.ino
+++ b/tasmota/tasmota_xdrv_driver/xdrv_01_9_webserver.ino
@@ -1885,21 +1885,23 @@ bool HandleRootStatusRefresh(void) {
   XsnsXdrvCall(FUNC_WEB_SENSOR);
   WSContentSend_P(PSTR("</table>"));
 
-  if (!Settings->flag6.gui_no_state_text &&  // SetOption161 - (GUI) Disable display of state text (1)
-      TasmotaGlobal.devices_present) {
+  if (!Settings->flag6.gui_no_state_text) {          // SetOption161 - (GUI) Disable display of state text (1)
+    if (!Web.buttons_non_light_non_shutter) {        // Might still be zero on restart so chk if we have at least one 
+      WebGetDeviceCounts();
+    }
+    if ((Web.buttons_non_light_non_shutter > 0) &&
+       ( Web.buttons_non_light_non_shutter <= 8)) {  // We need at least one non light AND non shutter button
 
 #ifdef USE_SONOFF_IFAN
-    if (IsModuleIfan()) {
-      WSContentSend_P(PSTR("{t}<tr>"));
-      WSContentSend_P(HTTP_DEVICE_STATE, 36, (bitRead(TasmotaGlobal.power, 0)) ? PSTR("bold") : PSTR("normal"), 54, GetStateText(bitRead(TasmotaGlobal.power, 0)));
-      uint32_t fanspeed = GetFanspeed();
-      snprintf_P(svalue, sizeof(svalue), PSTR("%d"), fanspeed);
-      WSContentSend_P(HTTP_DEVICE_STATE, 64, (fanspeed) ? PSTR("bold") : PSTR("normal"), 54, (fanspeed) ? svalue : GetStateText(0));
-      WSContentSend_P(PSTR("</tr></table>"));
-    } else {
+      if (IsModuleIfan()) {
+        WSContentSend_P(PSTR("{t}<tr>"));
+        WSContentSend_P(HTTP_DEVICE_STATE, 36, (bitRead(TasmotaGlobal.power, 0)) ? PSTR("bold") : PSTR("normal"), 54, GetStateText(bitRead(TasmotaGlobal.power, 0)));
+        uint32_t fanspeed = GetFanspeed();
+        snprintf_P(svalue, sizeof(svalue), PSTR("%d"), fanspeed);
+        WSContentSend_P(HTTP_DEVICE_STATE, 64, (fanspeed) ? PSTR("bold") : PSTR("normal"), 54, (fanspeed) ? svalue : GetStateText(0));
+        WSContentSend_P(PSTR("</tr></table>"));
+      } else {
 #endif  // USE_SONOFF_IFAN
-
-      if (Web.buttons_non_light_non_shutter <= 8) {   // Any non light AND non shutter button
         WSContentSend_P(PSTR("{t}<tr>"));
         uint32_t cols = Web.buttons_non_light_non_shutter;
         uint32_t fontsize = (cols < 5) ? 70 - (cols * 8) : 32;
@@ -1908,17 +1910,15 @@ bool HandleRootStatusRefresh(void) {
           if (bitRead(Web.light_shutter_button_mask, button_idx -1)) { continue; }  // Skip non-sequential shutter button
           bool power_state = bitRead(TasmotaGlobal.power, button_idx -1);
           snprintf_P(svalue, sizeof(svalue), PSTR("%d"), power_state);
-          WSContentSend_P(HTTP_DEVICE_STATE, 100 / cols, (power_state) ? "bold" : "normal", fontsize, (cols < 5) ? GetStateText(power_state) : svalue);
+          WSContentSend_P(HTTP_DEVICE_STATE, 100 / cols, (power_state) ? PSTR("bold") : PSTR("normal"), fontsize, (cols < 5) ? GetStateText(power_state) : svalue);
           button_ptr++;
-          if (button_ptr == Web.buttons_non_light_non_shutter) { break; }
+          if (button_ptr >= Web.buttons_non_light_non_shutter) { break; }
         }
         WSContentSend_P(PSTR("</tr></table>"));
-      }
-
 #ifdef USE_SONOFF_IFAN
-    }
+      }
 #endif  // USE_SONOFF_IFAN
-
+    }
   }
 
   if (1 == Web.slider_update_time) {
diff --git a/tasmota/tasmota_xdrv_driver/xdrv_13_display.ino b/tasmota/tasmota_xdrv_driver/xdrv_13_display.ino
index a6ebf1e6f..732586d65 100644
--- a/tasmota/tasmota_xdrv_driver/xdrv_13_display.ino
+++ b/tasmota/tasmota_xdrv_driver/xdrv_13_display.ino
@@ -1852,11 +1852,12 @@ void DisplayLocalSensor(void)
 \*********************************************************************************************/
 
 void DisplayInitDriver(void) {
-  Settings->display_model = 0;
+  uint32_t display_model = Settings->display_model;
+  Settings->display_model = 0;                    // Test if any display_model is available
   XdspCall(FUNC_DISPLAY_INIT_DRIVER);
-
-//  AddLog(LOG_LEVEL_DEBUG, PSTR(D_LOG_DEBUG "Display model %d"), Settings->display_model);
-
+  if (Settings->display_model) {                  // If model found keep using user configured one for backward compatibility
+    Settings->display_model = display_model;
+  }
   if (!Settings->display_model) { return; }
 
 //  AddLog(LOG_LEVEL_DEBUG_MORE, PSTR("DSP: Model %d"), Settings->display_model);
@@ -1891,15 +1892,6 @@ void DisplayInitDriver(void) {
 #endif
 
   UpdateDevicesPresent(1);
-  if (!PinUsed(GPIO_BACKLIGHT)) {
-    if ((LT_PWM1 == TasmotaGlobal.light_type) &&  // Single PWM light channel
-        (4 == Settings->display_model)            // ILI9341 legacy
-//          ((4 == Settings->display_model) ||        // ILI9341 legacy
-//           (17 == Settings->display_model))         // Universal - Too invasive in case displays have no backlight pin
-        ) {
-      UpdateDevicesPresent(-1);                   // Assume PWM channel is used for backlight
-    }
-  }
   disp_device = TasmotaGlobal.devices_present;
 
 #ifndef USE_DISPLAY_MODES1TO5