Consider port numbers with zero digits as empty, not 0 (fixes #3)

tests/test.c

@@ -202,6 +202,10 @@ static int json_to_url(cJSON *json, URL *url)
         url->fragment.len--;
     }
 
+    if (port.len == 0) {
+        url->no_port = 1;
+        url->port = 0;
+    } else {
         char tmp[8];
         if (port.len >= (int) sizeof(tmp)) {
             test_printf(" JSON object's port field is longer than expected\n");
@@ -210,7 +214,9 @@ static int json_to_url(cJSON *json, URL *url)
         memcpy(tmp, port.ptr, port.len);
         tmp[port.len] = 0;
 
+        url->no_port = 0;
         url->port = atoi(tmp);
+    }
     return 0;
 }
 
@@ -269,6 +275,20 @@ static int compare_urls(URL parsed, URL expected)
         ok = false;
     }
 
+    if (parsed.no_port != expected.no_port) {
+        if (ok) test_printf("\n");
+        if (parsed.no_port) {
+            test_printf("  port mismatch\n");
+            test_printf("    parsed   (empty)\n");
+            test_printf("    expected [%d]\n", expected.port);
+        } else {
+            test_printf("  port mismatch\n");
+            test_printf("    parsed   [%d]\n", parsed.port);
+            test_printf("    expected (empty)\n");
+        }
+        ok = false;
+    }
+
     if (parsed.port != expected.port) {
         if (ok) test_printf("\n");
         test_printf("  port mismatch\n");

url.c

@@ -580,6 +580,9 @@ int url_parse(char *src, int len, int *pcur, URL *out, int flags)
         out->no_port = 1;
         out->port    = 0;
         if (cur < len && src[cur] == ':') {
+            cur++; // Consume the ':'
+
+            if (cur < len && is_digit(src[cur])) {
 
                 // The WHATWG standard forbids port numbers with the
                 // "file" protocol.
@@ -588,17 +591,15 @@ int url_parse(char *src, int len, int *pcur, URL *out, int flags)
                         return -1;
                 }
 
-            cur++; // Consume the ':'
                 out->no_port = 0;
-
+                do {
-            while (cur < len && is_digit(src[cur])) {
-
                     int n = src[cur] - '0';
                     cur++;
 
                     if (out->port > (UINT16_MAX - n) / 10)
                         return -1; // Overflow
                     out->port = out->port * 10 + n;
+                } while (cur < len && is_digit(src[cur]));
             }
         }