Add additional safety checks: placeholder detection, division by zero prevention

Co-authored-by: sarpel <7412192+sarpel@users.noreply.github.com>

Author: Copilot

src/adaptive_buffer.cpp

@@ -89,6 +89,15 @@ void AdaptiveBuffer::updateBufferSize(int32_t rssi)
     // Only log if size changed significantly (>10%)
     if (new_size != current_buffer_size)
     {
+        // Prevent division by zero
+        if (current_buffer_size == 0)
+        {
+            current_buffer_size = new_size;
+            adjustment_count++;
+            last_adjustment_time = now;
+            return;
+        }
+
         int change_pct = ((int)new_size - (int)current_buffer_size) * 100 / (int)current_buffer_size;
 
         if (abs(change_pct) >= 10)

src/config_validator.h

@@ -76,6 +76,9 @@ class ConfigValidator {
         if (strlen(WIFI_SSID) == 0) {
             LOG_ERROR("WiFi SSID is empty - must configure WIFI_SSID in config.h");
             valid = false;
+        } else if (strcmp(WIFI_SSID, "YOUR_WIFI_SSID") == 0) {
+            LOG_ERROR("WiFi SSID is still set to default placeholder - must configure WIFI_SSID in config.h");
+            valid = false;
         } else {
             LOG_INFO("  ✓ WiFi SSID configured");
         }
@@ -84,6 +87,9 @@ class ConfigValidator {
         if (strlen(WIFI_PASSWORD) == 0) {
             LOG_ERROR("WiFi password is empty - must configure WIFI_PASSWORD in config.h");
             valid = false;
+        } else if (strcmp(WIFI_PASSWORD, "YOUR_WIFI_PASSWORD") == 0) {
+            LOG_ERROR("WiFi password is still set to default placeholder - must configure WIFI_PASSWORD in config.h");
+            valid = false;
         } else {
             LOG_INFO("  ✓ WiFi password configured");
         }
@@ -123,6 +129,9 @@ class ConfigValidator {
         if (strlen(SERVER_HOST) == 0) {
             LOG_ERROR("Server HOST is empty - must configure SERVER_HOST in config.h");
             valid = false;
+        } else if (strcmp(SERVER_HOST, "YOUR_SERVER_IP") == 0) {
+            LOG_ERROR("Server HOST is still set to default placeholder - must configure SERVER_HOST in config.h");
+            valid = false;
         } else {
             LOG_INFO("  ✓ Server HOST configured: %s", SERVER_HOST);
         }

src/logger.cpp

@@ -46,6 +46,12 @@ void Logger::init(LogLevel level)
 
 void Logger::log(LogLevel level, const char *file, int line, const char *fmt, ...)
 {
+    // Validate input parameters
+    if (file == nullptr || fmt == nullptr)
+    {
+        return; // Silently ignore invalid calls to prevent recursion
+    }
+
     if (level < min_level)
         return;
 

src/main.cpp

@@ -119,7 +119,12 @@ void checkMemoryHealth() {
     if (free_heap < MEMORY_CRITICAL_THRESHOLD) {
         LOG_CRITICAL("Critical low memory: %u bytes - system may crash", free_heap);
         // Consider restarting if critically low
-        if (free_heap < MEMORY_CRITICAL_THRESHOLD / 2) {
+        // Use a safer threshold calculation
+        uint32_t emergency_threshold = MEMORY_CRITICAL_THRESHOLD / 2;
+        if (emergency_threshold == 0) {
+            emergency_threshold = 1000; // Minimum 1KB emergency threshold
+        }
+        if (free_heap < emergency_threshold) {
             LOG_CRITICAL("Memory critically low - initiating graceful restart");
             gracefulShutdown();
             ESP.restart();