Fixes #1520: crash in activating HTTP/1 observer (#1521)

Add more HTTP/1.x observer and decoder unit tests and bugfixes.

src/decoders/http1/http1_decoder.c

@@ -749,42 +749,35 @@ static bool parse_header(qd_http1_decoder_connection_t *hconn, decoder_t *decode
         // need more data
         return false;
 
-    size_t in_octets = strlen(line);
-    char *eol = &line[in_octets];  // eol points to null terminator
-
     debug_print_line("header:", line);
 
-    if (in_octets == 0) {
+    if (*line == '\0') {
         // empty header == end of headers
         bool ok = headers_done(hconn, decoder);
         if (!ok)
             return false;
         return !!(*length);
     }
 
-    // TODO: support obsolete line folding. For now I punt:
+    // TODO: support obsolete line folding. For now I punt and ignore the continued header
     if (*line == ' ' || *line == '\t')
         return !!(*length);
 
     // parse out key/value
 
     char *saveptr = 0;
     char *key = strtok_r(line, ":", &saveptr);
+    char *value = strtok_r(0, "", &saveptr);
 
-    if (!key) {
-        parser_error(hconn, "Malformed header key");
-        return false;
+    if (!key || *key == '\0' || !value) {
+        // Unable to parse this header, skip it
+        return !!(*length);
     }
 
     // According to RFC9112, the key is immediately followed by ':'. Value may start and end with whitespace which must
     // be removed before value can be processed.
-
-    char *value = &key[strlen(key)];  // value points to null at end of key
-    if (value < eol) {
-        value++;  // skip to start of value
-        value = trim_whitespace(value);
-        truncate_whitespace(value);
-    }
+    value = trim_whitespace(value);
+    truncate_whitespace(value);
 
     if (hconn->config->rx_header) {
         assert(decoder->hrs);

src/observers/tcp_observer.c

@@ -60,14 +60,17 @@ static void activate_inner(qdpo_transport_handle_t *th, qd_protocol_t inner_prot
             break;
     }
 
-    // pass save data to new observer
+    // Pass save data to new observer. The observer may deregister itself if a parse error is encountered so avoid
+    // passing data if that occurs.
 
     th->observe(th, true, save.prefix, save.prefix_len);
-    th->observe(th, true, data, length);
+    if (th->observe)
+        th->observe(th, true, data, length);
     qd_buffer_t *buf = DEQ_HEAD(save.server_data);
     while (buf) {
         DEQ_REMOVE_HEAD(save.server_data);
-        th->observe(th, false, qd_buffer_base(buf), qd_buffer_size(buf));
+        if (th->observe)
+            th->observe(th, false, qd_buffer_base(buf), qd_buffer_size(buf));
         qd_buffer_free(buf);
         buf = DEQ_HEAD(save.server_data);
     }