Fixed bug #39869 (safe_read does not initialize errno). (michiel at boland dot org)

NEWS

@@ -8,6 +8,8 @@ PHP                                                                        NEWS
   . cookies
   . canary protection (debug build only)
   . random generation of cookies and canaries
+- Fixed bug #39869 (safe_read does not initialize errno).
+  (michiel at boland dot org, Dmitry)
 - Fixed bug #39850 (SplFileObject throws contradictory/wrong error messages 
   when trying to open "php://wrong"). (Tony)
 - Fixed bug #39832 (SOAP Server: parameter not matching the WSDL specified type

sapi/cgi/fastcgi.c

@@ -347,6 +347,7 @@ static inline ssize_t safe_write(fcgi_request *req, const void *buf, size_t coun
 	size_t n = 0;
 
 	do {
+		errno = 0;
 		ret = write(req->fd, ((char*)buf)+n, count-n);
 		if (ret > 0) {
 			n += ret;
@@ -363,6 +364,7 @@ static inline ssize_t safe_read(fcgi_request *req, const void *buf, size_t count
 	size_t n = 0;
 
 	do {
+		errno = 0;
 		ret = read(req->fd, ((char*)buf)+n, count-n);
 		if (ret > 0) {
 			n += ret;