@@ -640,8 +640,9 @@ static void mi_option_init(mi_option_desc_t* desc) {
     }
     else {
       char* end = buf;
+      errno = 0;
       long value = strtol(buf, &end, 10);
-      if (mi_option_has_size_in_kib(desc->option)) {
+      if (errno==0 && mi_option_has_size_in_kib(desc->option)) {
         // this option is interpreted in KiB to prevent overflow of `long` for large allocations
         // (long is 32-bit on 64-bit windows, which allows for 4TiB max.)
         size_t size = (value < 0 ? 0 : (size_t)value);
@@ -656,7 +657,7 @@ static void mi_option_init(mi_option_desc_t* desc) {
         if (overflow || size > (MI_MAX_ALLOC_SIZE / MI_KiB)) { size = (MI_MAX_ALLOC_SIZE / MI_KiB); }
         value = (size > LONG_MAX ? LONG_MAX : (long)size);
       }
-      if (*end == 0) {
+      if (errno==0 && *end == 0) {
         mi_option_set(desc->option, value);
       }
       else {
Original file line number	Diff line number	Diff line change
@@ -640,8 +640,9 @@ static void mi_option_init(mi_option_desc_t* desc) {
640	640	}
641	641	else {
642	642	char* end = buf;
	643	+ errno = 0;
643	644	long value = strtol(buf, &end, 10);
644		- if (mi_option_has_size_in_kib(desc->option)) {
	645	+ if (errno==0 && mi_option_has_size_in_kib(desc->option)) {
645	646	// this option is interpreted in KiB to prevent overflow of `long` for large allocations
646	647	// (long is 32-bit on 64-bit windows, which allows for 4TiB max.)
647	648	size_t size = (value < 0 ? 0 : (size_t)value);
@@ -656,7 +657,7 @@ static void mi_option_init(mi_option_desc_t* desc) {
656	657	if (overflow \|\| size > (MI_MAX_ALLOC_SIZE / MI_KiB)) { size = (MI_MAX_ALLOC_SIZE / MI_KiB); }
657	658	value = (size > LONG_MAX ? LONG_MAX : (long)size);
658	659	}
659		- if (*end == 0) {
	660	+ if (errno==0 && *end == 0) {
660	661	mi_option_set(desc->option, value);
661	662	}
662	663	else {