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marlin "Multiplication of an int with 1000 may overflow in 16-bit architectures

Period_seconds * 1000 may overflow in 16-bit architectures, resulting in a wraparound, thus a negative result. This negative integer, when interpreted as an unsigned long, it's a very large number. Thus the comparison may always yield false. Issue 1309: https://github.com/MarlinFirmware/Marlin/pull/1309"

Bug fixed by commit 30248214c7f

Type	IntegerOverflow
Config	"THERMAL_RUNAWAY_PROTECTION_PERIOD && THERMAL_RUNAWAY_PROTECTION_PERIOD > 0" (2nd degree)
Fix-in	code
Location	temperature/

#include <stdio.h>

unsigned long millis = 123456789l;
#if defined (THERMAL_RUNAWAY_PROTECTION_PERIOD) && THERMAL_RUNAWAY_PROTECTION_PERIOD > 0
void thermal_runaway_protection(int *state, unsigned long *timer, float temperature, float target_temperature, int heater_id, int period_seconds, int hysteresis_degc)
{
if (temperature >= (target_temperature - hysteresis_degc))
      {
        *timer = 123456782l;
      } 
      else if ( (millis - *timer) > (period_seconds) * 1000)
      {
        printf("%s","Thermal Runaway, system stopped! Heater_ID: ");
        printf("%d",(int)heater_id);
        printf("%s","THERMAL RUNAWAY");
      }
 }
#endif

int main(void){
  thermal_runaway_protection(0, 123456783, 145.0f, 200.0f, 1, 10, 1);
  return 0;
}

diff --git a/simple/3024821.c b/simple/3024821.c
--- a/simple/3024821.c
+++ b/simple/3024821.c
@@ -8,7 +8,7 @@ if (temperature >= (target_temperature - hysteresis_degc))
       {
         *timer = 123456782l;
       } 
-      else if ( (millis - *timer) > (period_seconds) * 1000)
+      else if ( (millis - *timer) > (unsigned long)(period_seconds) * 1000)
       {
         printf("%s","Thermal Runaway, system stopped! Heater_ID: ");
         printf("%d",(int)heater_id);

#include <stdio.h>

int main(void){
unsigned long millis = 123456789l;
#if defined (THERMAL_RUNAWAY_PROTECTION_PERIOD) && THERMAL_RUNAWAY_PROTECTION_PERIOD > 0
  int state = 0;
  unsigned long *timer = 123456782l;
  float temperature = 145.0f;
  float target_temperature = 200.0f;
  int heater_id = 1;
  int period_seconds = 10;
  int hysteresis_degc = 1;
  
  
if (temperature >= (target_temperature - hysteresis_degc))
      {
        *timer = 123456782;
      } 
      else if ( (millis - *timer) > (period_seconds) * 1000)
      {
        printf("%s","Thermal Runaway, system stopped! Heater_ID: ");
        printf("%d",(int)heater_id);
        printf("%s","THERMAL RUNAWAY");
      }
 
#endif
return 0;
}

. call  Marlin/temperature.cpp:1017: void thermal_runaway_protection(...)
. ERROR temperature.cpp:1052:  else if ( (millis() - *timer) > (period_seconds) * 1000) // Comparing an unsigned long with an integer...