[multiple] Add division by zero guards (#14634)

Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>
Co-authored-by: J. Nick Koston <nick+github@koston.org>

esphome/components/bl0942/bl0942.cpp

@@ -173,7 +173,7 @@ void BL0942::received_package_(DataPacket *data) {
   float i_rms = (uint24_t) data->i_rms / current_reference_;
   float watt = (int24_t) data->watt / power_reference_;
   float total_energy_consumption = cf_cnt / energy_reference_;
-  float frequency = 1000000.0f / data->frequency;
+  float frequency = data->frequency != 0 ? 1000000.0f / data->frequency : NAN;
 
   if (voltage_sensor_ != nullptr) {
     voltage_sensor_->publish_state(v_rms);

esphome/components/combination/combination.cpp

@@ -163,7 +163,7 @@ void MeanCombinationComponent::handle_new_value(float value) {
     return;
 
   float sum = 0.0;
-  size_t count = 0.0;
+  size_t count = 0;
 
   for (const auto &sensor : this->sensors_) {
     if (std::isfinite(sensor->state)) {
@@ -172,6 +172,10 @@ void MeanCombinationComponent::handle_new_value(float value) {
     }
   }
 
+  if (count == 0) {
+    this->publish_state(NAN);
+    return;
+  }
   float mean = sum / count;
 
   this->publish_state(mean);
@@ -238,6 +242,11 @@ void RangeCombinationComponent::handle_new_value(float value) {
     }
   }
 
+  if (sensor_states.empty()) {
+    this->publish_state(NAN);
+    return;
+  }
+
   sort(sensor_states.begin(), sensor_states.end());
 
   float range = sensor_states.back() - sensor_states.front();

esphome/components/graph/graph.cpp

@@ -171,7 +171,7 @@ void Graph::draw(Display *buff, uint16_t x_offset, uint16_t y_offset, Color colo
     bool prev_b = false;
     int16_t prev_y = 0;
     for (uint32_t i = 0; i < this->width_; i++) {
-      float v = (trace->get_tracedata()->get_value(i) - ymin) / yrange;
+      float v = yrange != 0 ? (trace->get_tracedata()->get_value(i) - ymin) / yrange : NAN;
       if (!std::isnan(v) && (thick > 0)) {
         int16_t x = this->width_ - 1 - i + x_offset;
         uint8_t bit = 1 << ((i % (thick * LineType::PATTERN_LENGTH)) / thick);

esphome/components/mics_4514/mics_4514.cpp

@@ -59,6 +59,12 @@ void MICS4514Component::update() {
     return;
   }
 
+  if (this->red_calibration_ == 0 || this->ox_calibration_ == 0) {
+    ESP_LOGW(TAG, "Calibration values are zero, retrying");
+    this->status_set_warning();
+    this->initial_ = true;
+    return;
+  }
   float red_f = (float) (power - red) / this->red_calibration_;
   float ox_f = (float) (power - ox) / this->ox_calibration_;
 

esphome/components/tsl2561/tsl2561.cpp

@@ -70,6 +70,10 @@ float TSL2561Sensor::calculate_lx_(uint16_t ch0, uint16_t ch1) {
     return NAN;
   }
 
+  if (ch0 == 0) {
+    ESP_LOGVV(TAG, "No light detected");
+    return 0.0f;
+  }
   float d0 = ch0, d1 = ch1;
   float ratio = d1 / d0;
 

esphome/components/ufire_ec/ufire_ec.cpp

@@ -1,5 +1,6 @@
 #include "esphome/core/log.h"
 #include "ufire_ec.h"
+#include <cmath>
 
 namespace esphome {
 namespace ufire_ec {
@@ -60,9 +61,15 @@ float UFireECComponent::measure_temperature_() { return this->read_data_(REGISTE
 
 float UFireECComponent::measure_ms_() { return this->read_data_(REGISTER_MS); }
 
-void UFireECComponent::set_solution_(float solution, float temperature) {
-  solution /= (1 - (this->temperature_coefficient_ * (temperature - 25)));
+bool UFireECComponent::set_solution_(float solution, float temperature) {
+  float denom = 1 - (this->temperature_coefficient_ * (temperature - 25));
+  if (std::abs(denom) < 1e-6f) {
+    ESP_LOGE(TAG, "Temperature compensation denominator is zero");
+    return false;
+  }
+  solution /= denom;
   this->write_data_(REGISTER_SOLUTION, solution);
+  return true;
 }
 
 void UFireECComponent::set_compensation_(float temperature) { this->write_data_(REGISTER_COMPENSATION, temperature); }
@@ -72,7 +79,8 @@ void UFireECComponent::set_coefficient_(float coefficient) { this->write_data_(R
 void UFireECComponent::set_temperature_(float temperature) { this->write_data_(REGISTER_TEMP, temperature); }
 
 void UFireECComponent::calibrate_probe(float solution, float temperature) {
-  this->set_solution_(solution, temperature);
+  if (!this->set_solution_(solution, temperature))
+    return;
   this->write_byte(REGISTER_TASK, COMMAND_CALIBRATE_PROBE);
 }
 

esphome/components/ufire_ec/ufire_ec.h

@@ -44,7 +44,7 @@ class UFireECComponent : public PollingComponent, public i2c::I2CDevice {
  protected:
   float measure_temperature_();
   float measure_ms_();
-  void set_solution_(float solution, float temperature);
+  bool set_solution_(float solution, float temperature);
   void set_compensation_(float temperature);
   void set_coefficient_(float coefficient);
   void set_temperature_(float temperature);

esphome/components/xxtea/xxtea.cpp

@@ -7,6 +7,8 @@ static const uint32_t DELTA = 0x9e3779b9;
 #define MX ((((z >> 5) ^ (y << 2)) + ((y >> 3) ^ (z << 4))) ^ ((sum ^ y) + (k[(p ^ e) & 7] ^ z)))
 
 void encrypt(uint32_t *v, size_t n, const uint32_t *k) {
+  if (n == 0)
+    return;
   uint32_t z, y, sum, e;
   size_t p;
   size_t q = 6 + 52 / n;
@@ -25,6 +27,8 @@ void encrypt(uint32_t *v, size_t n, const uint32_t *k) {
 }
 
 void decrypt(uint32_t *v, size_t n, const uint32_t *k) {
+  if (n == 0)
+    return;
   uint32_t z, y, sum, e;
   size_t p;
   size_t q = 6 + 52 / n;