For functions that write to an output buffer, ignore the buffer pointer if the passed capacity is set to 0

README.md

@@ -1,5 +1,5 @@
 # url.c
-This is a small library to parse and manipulate URLs in conformance to RFC 3986 and WHATWG.
+This is a small library to parse and manipulate URLs in conformance to RFC 3986 and (most of) the WHATWG specification.
 
 It features
 * No allocations
@@ -15,6 +15,4 @@ You just copy paste `url.h` and `url.c` in your source tree and compile them as
 Some example programs are provided in the `examples/` folder. To compile them, run `build.bat` on Windows or `build.sh` on Linux.
 
 # Testing
-The parser and reference resolver is tested against the URL section of the [web platform tests](https://github.com/web-platform-tests/wpt). Note that not all tests pass. This is due to the parser not doing any normalization and not supporting more niche features such as converting `\` characters to `/` or supporting drive letters like `C:` in the URL's path.
+The parser and reference resolver is tested against the URL section of the [web platform tests](https://github.com/web-platform-tests/wpt), which validates implementations that adhere to the WHATWG specification (what the major browsers actually do). To run the test suite, `cd` into `tests/` and compile the test runner using `build.sh` (Linux) or `build.bat` (Windows). Then, run `./test.out` (Linux) or `./test.exe` (Windows). Note that not all tests pass, which is to be expected as adherence to the WHATWG specification is a work-in-progress.
-
-To run the test suite, `cd` into `tests/` and compile the test runner using `build.sh` (Linux) or `build.bat` (Windows). Then, run `./test.out` (Linux) or `./test.exe` (Windows).

tests/test.c

@@ -31,6 +31,10 @@ void test_printf(char *fmt, ...)
         sizeof(test_output_buffer) - test_output_buffer_used,
         fmt, args);
     va_end(args);
+
+    assert(len > -1);
+    if (len > (int) sizeof(test_output_buffer) - test_output_buffer_used)
+        len = sizeof(test_output_buffer) - test_output_buffer_used;
     test_output_buffer_used += len;
 }
 
@@ -198,6 +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");
@@ -206,7 +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;
 }
 
@@ -265,6 +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");
@@ -488,6 +512,7 @@ int main(void)
 
     if (!cJSON_IsArray(root)) {
         fprintf(stderr, "Error: %s doesn't contain a JSON array as expected", path);
+        cJSON_Delete(root);
         free(buf);
         return -1;
     }
@@ -540,6 +565,7 @@ int main(void)
     printf("  failed : %d\n", num_failed);
     printf("  aborted: %d\n", num_aborted);
 
+    cJSON_Delete(root);
     free(buf);
     return 0;
 }

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]));
             }
         }
 
@@ -856,6 +857,8 @@ static void append_fragment(Builder *b, URL_String fragment)
 
 int url_serialize(URL url, URL *base, char *dst, int cap)
 {
+    ASSERT(cap == 0 || dst != NULL);
+
     if (base != NULL && base->scheme.len == 0)
         return -1; // Base is not an absolute URL
 
@@ -959,6 +962,8 @@ static URL_b32 is_white_space(char c)
 
 int url_remove_white_space(char *src, int len, char *dst, int cap)
 {
+    ASSERT(cap == 0 || dst != NULL);
+
     while (len > 0 && is_white_space(src[0])) {
         src++;
         len--;
@@ -981,6 +986,8 @@ int url_remove_white_space(char *src, int len, char *dst, int cap)
 
 int url_percent_decode(URL_String str, char *dst, int cap)
 {
+    ASSERT(cap == 0 || dst != NULL);
+
     char *src = str.ptr;
     int   len = str.len;
     int   rd  = 0;