fix getaddrinfo to accept port 0 (zero)

new behavior can be summarized as:
inputs that parse completely as a decimal number are treated as one,
and rejected only if the result is out of 16-bit range.
inputs that do not parse as a decimal number (where strtoul leaves
anything left over in the input) are searched in /etc/services.

diff --git a/src/network/getaddrinfo.c b/src/network/getaddrinfo.c
index b9e562f..b341912 100644 (file)
--- a/src/network/getaddrinfo.c
+++ b/src/network/getaddrinfo.c
@@ -76,8 +76,7 @@ int getaddrinfo(const char *restrict host, const char *restrict serv, const stru
        if (serv) {
                if (!*serv) return EAI_SERVICE;
                port = strtoul(serv, &z, 10);
-               if (!*z && port > 65535) return EAI_SERVICE;
-               if (!port) {
+               if (*z) {
                        size_t servlen = strlen(serv);
                        char *end = line;
 
@@ -96,6 +95,7 @@ int getaddrinfo(const char *restrict host, const char *restrict serv, const stru
                        __fclose_ca(f);
                        if (feof(f)) return EAI_SERVICE;
                }
+               if (port > 65535) return EAI_SERVICE;
                port = htons(port);
        }