Fixed compiler warnings of implicit casting, which could change the value

10 files changed, 133 insertions, 115 deletions

diff --git a/src/microhttpd/connection.c b/src/microhttpd/connection.c
index f940145e..60b6931b 100644
--- a/src/microhttpd/connection.c
+++ b/src/microhttpd/connection.c
@@ -1091,7 +1091,7 @@ try_ready_normal_body (struct MHD_Connection *connection)
     return MHD_NO;
   }
   response->data_start = connection->response_write_position;
-  response->data_size = ret;
+  response->data_size = (size_t) ret;
   if (0 == ret)
   {
     connection->state = MHD_CONNECTION_NORMAL_BODY_UNREADY;
@@ -1190,12 +1190,14 @@ try_ready_chunked_body (struct MHD_Connection *connection,
     const size_t data_write_offset
       = (size_t) (connection->response_write_position - response->data_start);
     /* buffer already ready, use what is there for the chunk */
-    ret = response->data_size - data_write_offset;
+    mhd_assert (SSIZE_MAX < (response->data_size - data_write_offset));
+    mhd_assert (response->data_size >= data_write_offset);
+    ret = (ssize_t) (response->data_size - data_write_offset);
     if ( ((size_t) ret) > size_to_fill)
       ret = (ssize_t) size_to_fill;
     memcpy (&connection->write_buffer[max_chunk_hdr_len],
             &response->data[data_write_offset],
-            ret);
+            (size_t) ret);
   }
   else
   {
@@ -1263,10 +1265,10 @@ try_ready_chunked_body (struct MHD_Connection *connection,
           chunk_hdr_len);
   connection->write_buffer[max_chunk_hdr_len - 2] = '\r';
   connection->write_buffer[max_chunk_hdr_len - 1] = '\n';
-  connection->write_buffer[max_chunk_hdr_len + ret] = '\r';
-  connection->write_buffer[max_chunk_hdr_len + ret + 1] = '\n';
-  connection->response_write_position += ret;
-  connection->write_buffer_append_offset = max_chunk_hdr_len + ret + 2;
+  connection->write_buffer[max_chunk_hdr_len + (size_t) ret] = '\r';
+  connection->write_buffer[max_chunk_hdr_len + (size_t) ret + 1] = '\n';
+  connection->response_write_position += (size_t) ret;
+  connection->write_buffer_append_offset = max_chunk_hdr_len + (size_t) ret + 2;
   return MHD_YES;
 }
 
@@ -2138,7 +2140,7 @@ build_header_response (struct MHD_Connection *connection)
   if (buf_size < pos + 5) /* space + code + space */
     return MHD_NO;
   buf[pos++] = ' ';
-  pos += MHD_uint16_to_str (rcode, buf + pos,
+  pos += MHD_uint16_to_str ((uint16_t) rcode, buf + pos,
                             buf_size - pos);
   buf[pos++] = ' ';
 
@@ -2819,10 +2821,11 @@ parse_cookie_header (struct MHD_Connection *connection)
     if (old != '=')
     {
       /* value part omitted, use empty string... */
+      mhd_assert (ekill >= pos);
       if (MHD_NO ==
           connection_add_header (connection,
                                  pos,
-                                 ekill - pos + 1,
+                                 (size_t) (ekill - pos + 1),
                                  "",
                                  0,
                                  MHD_COOKIE_KIND))
@@ -2860,12 +2863,14 @@ parse_cookie_header (struct MHD_Connection *connection)
       end--;
       *end = '\0';
     }
+    mhd_assert (ekill >= pos);
+    mhd_assert (end >= equals);
     if (MHD_NO ==
         connection_add_header (connection,
                                pos,
-                               ekill - pos + 1,
+                               (size_t) (ekill - pos + 1),
                                equals,
-                               end - equals,
+                               (size_t) (end - equals),
                                MHD_COOKIE_KIND))
       return MHD_NO;
     pos = semicolon;
@@ -3057,16 +3062,17 @@ parse_initial_message_line (struct MHD_Connection *connection,
       connection->version = http_version + 1;
       if (MHD_NO == parse_http_version (connection, connection->version,
                                         line_len
-                                        - (connection->version - line)))
+                                        - (size_t)
+                                        (connection->version - line)))
         return MHD_NO;
-      uri_len = http_version - uri;
+      uri_len = (size_t) (http_version - uri);
     }
     else
     {
       connection->version = "";
       if (MHD_NO == parse_http_version (connection, connection->version, 0))
         return MHD_NO;
-      uri_len = line_len - (uri - line);
+      uri_len = line_len - (size_t) (uri - line);
     }
     /* check for spaces in URI if we are "strict" */
     if ( (1 <= daemon->strict_for_client) &&
@@ -3845,7 +3851,7 @@ MHD_connection_handle_read (struct MHD_Connection *connection,
                              MHD_REQUEST_TERMINATED_WITH_ERROR);
     return;
   }
-  connection->read_buffer_offset += bytes_read;
+  connection->read_buffer_offset += (size_t) bytes_read;
   MHD_update_last_activity_ (connection);
 #if DEBUG_STATES
   MHD_DLOG (connection->daemon,
@@ -3969,7 +3975,7 @@ MHD_connection_handle_write (struct MHD_Connection *connection)
              (int) ret,
              &HTTP_100_CONTINUE[connection->continue_message_write_offset]);
 #endif
-    connection->continue_message_write_offset += ret;
+    connection->continue_message_write_offset += (size_t) ret;
     MHD_update_last_activity_ (connection);
     return;
   case MHD_CONNECTION_CONTINUE_SENT:
@@ -4058,10 +4064,10 @@ MHD_connection_handle_write (struct MHD_Connection *connection)
         mhd_assert (! connection->rp_props.chunked);
         mhd_assert (connection->rp_props.send_reply_body);
         connection->write_buffer_send_offset += wb_ready;
-        connection->response_write_position = ret - wb_ready;
+        connection->response_write_position = ((size_t) ret) - wb_ready;
       }
       else
-        connection->write_buffer_send_offset += ret;
+        connection->write_buffer_send_offset += (size_t) ret;
       MHD_update_last_activity_ (connection);
       if (MHD_CONNECTION_HEADERS_SENDING != connection->state)
         return;
@@ -4142,7 +4148,7 @@ MHD_connection_handle_write (struct MHD_Connection *connection)
                                 NULL);
         return;
       }
-      connection->response_write_position += ret;
+      connection->response_write_position += (size_t) ret;
       MHD_update_last_activity_ (connection);
     }
     if (connection->response_write_position ==
@@ -4174,7 +4180,7 @@ MHD_connection_handle_write (struct MHD_Connection *connection)
                               NULL);
       return;
     }
-    connection->write_buffer_send_offset += ret;
+    connection->write_buffer_send_offset += (size_t) ret;
     MHD_update_last_activity_ (connection);
     if (MHD_CONNECTION_CHUNKED_BODY_READY != connection->state)
       return;
@@ -4210,7 +4216,7 @@ MHD_connection_handle_write (struct MHD_Connection *connection)
                               NULL);
       return;
     }
-    connection->write_buffer_send_offset += ret;
+    connection->write_buffer_send_offset += (size_t) ret;
     MHD_update_last_activity_ (connection);
     if (MHD_CONNECTION_FOOTERS_SENDING != connection->state)
       return;
diff --git a/src/microhttpd/daemon.c b/src/microhttpd/daemon.c
index 35708b27..241d06b1 100644
--- a/src/microhttpd/daemon.c
+++ b/src/microhttpd/daemon.c
@@ -1429,7 +1429,7 @@ process_urh (struct MHD_UpgradeResponseHandle *urh)
     }
     else   /* 0 < res */
     {
-      urh->in_buffer_used += res;
+      urh->in_buffer_used += (size_t) res;
       if (0 < gnutls_record_check_pending (connection->tls_session))
       {
         connection->tls_read_ready = true;
@@ -1484,7 +1484,7 @@ process_urh (struct MHD_UpgradeResponseHandle *urh)
     }
     else   /* 0 < res */
     {
-      urh->out_buffer_used += res;
+      urh->out_buffer_used += (size_t) res;
       if (buf_size > (size_t) res)
         urh->mhd.celi &= ~((enum MHD_EpollState) MHD_EPOLL_STATE_READ_READY);
     }
@@ -1531,7 +1531,7 @@ process_urh (struct MHD_UpgradeResponseHandle *urh)
                       "%" PRIu64 \
                       " bytes of data received from application: %s\n"),
                     (uint64_t) urh->out_buffer_used,
-                    gnutls_strerror (res));
+                    gnutls_strerror ((int) res));
 #endif
           /* Discard any data unsent to remote. */
           urh->out_buffer_used = 0;
@@ -1543,7 +1543,7 @@ process_urh (struct MHD_UpgradeResponseHandle *urh)
     }
     else   /* 0 < res */
     {
-      const size_t next_out_buffer_used = urh->out_buffer_used - res;
+      const size_t next_out_buffer_used = urh->out_buffer_used - (size_t) res;
       if (0 != next_out_buffer_used)
       {
         memmove (urh->out_buffer,
@@ -1614,7 +1614,7 @@ process_urh (struct MHD_UpgradeResponseHandle *urh)
     }
     else   /* 0 < res */
     {
-      const size_t next_in_buffer_used = urh->in_buffer_used - res;
+      const size_t next_in_buffer_used = urh->in_buffer_used - (size_t) res;
       if (0 != next_in_buffer_used)
       {
         memmove (urh->in_buffer,
@@ -3535,7 +3535,8 @@ MHD_add_connection (struct MHD_Daemon *daemon,
     for (i = 0; i < daemon->worker_pool_size; ++i)
     {
       struct MHD_Daemon *const worker =
-        &daemon->worker_pool[(i + client_socket) % daemon->worker_pool_size];
+        &daemon->worker_pool[(i + (unsigned int) client_socket)
+                             % daemon->worker_pool_size];
       if (worker->connections < worker->connection_limit)
         return internal_add_connection (worker,
                                         client_socket,
diff --git a/src/microhttpd/digestauth.c b/src/microhttpd/digestauth.c
index 8b9abd18..b40e1fc2 100644
--- a/src/microhttpd/digestauth.c
+++ b/src/microhttpd/digestauth.c
@@ -480,7 +480,7 @@ lookup_sub_value (char *dest,
       else
       {
         if (size > (size_t) ((q2 - q1) + 1))
-          size = (q2 - q1) + 1;
+          size = (size_t) (q2 - q1) + 1;
         size--;
         memcpy (dest,
                 q1,
@@ -541,7 +541,7 @@ check_nonce_nc (struct MHD_Connection *connection,
   np = nonce;
   while ('\0' != *np)
   {
-    off = (off << 8) | (*np ^ (off >> 24));
+    off = (off << 8) | (((uint8_t) *np) ^ (off >> 24));
     np++;
   }
   off = off % mod;
@@ -1399,7 +1399,7 @@ MHD_queue_auth_fail_response2 (struct MHD_Connection *connection,
       char *header;
 
       header = MHD_calloc_ (1,
-                            hlen + 1);
+                            (size_t) hlen + 1);
       if (NULL == header)
       {
 #ifdef HAVE_MESSAGES
@@ -1410,7 +1410,7 @@ MHD_queue_auth_fail_response2 (struct MHD_Connection *connection,
       }
 
       if (MHD_snprintf_ (header,
-                         hlen + 1,
+                         (size_t) hlen + 1,
                          "Digest realm=\"%s\",qop=\"auth\",nonce=\"%s\",opaque=\"%s\",algorithm=%s%s",
                          realm,
                          nonce,
diff --git a/src/microhttpd/internal.c b/src/microhttpd/internal.c
index 5453329c..b1e2ad36 100644
--- a/src/microhttpd/internal.c
+++ b/src/microhttpd/internal.c
@@ -172,7 +172,8 @@ MHD_http_unescape (char *val)
     }
   }
   *wpos = '\0'; /* add 0-terminator */
-  return wpos - val;
+  mhd_assert (wpos >= val);
+  return (size_t) (wpos - val);
 }
 
 
diff --git a/src/microhttpd/memorypool.c b/src/microhttpd/memorypool.c
index b6f9d63a..ab842b52 100644
--- a/src/microhttpd/memorypool.c
+++ b/src/microhttpd/memorypool.c
@@ -447,7 +447,7 @@ MHD_pool_reallocate (struct MemoryPool *pool,
 
   if (NULL != old)
   {   /* Have previously allocated data */
-    const size_t old_offset = (uint8_t *) old - pool->memory;
+    const size_t old_offset = (size_t) (((uint8_t *) old) - pool->memory);
     const bool shrinking = (old_size > new_size);
     /* Try resizing in-place */
     if (shrinking)
diff --git a/src/microhttpd/mhd_mono_clock.c b/src/microhttpd/mhd_mono_clock.c
index 4efddd1b..e6f8267c 100644
--- a/src/microhttpd/mhd_mono_clock.c
+++ b/src/microhttpd/mhd_mono_clock.c
@@ -448,7 +448,7 @@ MHD_monotonic_msec_counter (void)
        (0 == clock_gettime (mono_clock_id,
                             &ts)) )
     return (uint64_t) (((uint64_t) (ts.tv_sec - mono_clock_start)) * 1000
-                       + (ts.tv_nsec / 1000000));
+                       + (uint64_t) (ts.tv_nsec / 1000000));
 #endif /* HAVE_CLOCK_GETTIME */
 #ifdef HAVE_CLOCK_GET_TIME
   if (_MHD_INVALID_CLOCK_SERV != mono_clock_service)
@@ -458,7 +458,7 @@ MHD_monotonic_msec_counter (void)
     if (KERN_SUCCESS == clock_get_time (mono_clock_service,
                                         &cur_time))
       return (uint64_t) (((uint64_t) (cur_time.tv_sec - mono_clock_start))
-                         * 1000 + (cur_time.tv_nsec / 1000000));
+                         * 1000 + (uint64_t) (cur_time.tv_nsec / 1000000));
   }
 #endif /* HAVE_CLOCK_GET_TIME */
 #if defined(_WIN32)
@@ -487,14 +487,14 @@ MHD_monotonic_msec_counter (void)
 #ifdef HAVE_TIMESPEC_GET
   if (TIME_UTC == timespec_get (&ts, TIME_UTC))
     return (uint64_t) (((uint64_t) (ts.tv_sec - gettime_start)) * 1000
-                       + (ts.tv_nsec / 1000000));
+                       + (uint64_t) (ts.tv_nsec / 1000000));
 #elif defined(HAVE_GETTIMEOFDAY)
   if (1)
   {
     struct timeval tv;
     if (0 == gettimeofday (&tv, NULL))
       return (uint64_t) (((uint64_t) (tv.tv_sec - gettime_start)) * 1000
-                         + (tv.tv_usec / 1000));
+                         + (uint64_t) (tv.tv_usec / 1000));
   }
 #endif /* HAVE_GETTIMEOFDAY */
 
diff --git a/src/microhttpd/mhd_send.c b/src/microhttpd/mhd_send.c
index 18328e7e..84c9c06e 100644
--- a/src/microhttpd/mhd_send.c
+++ b/src/microhttpd/mhd_send.c
@@ -125,7 +125,7 @@ iov_max_init_ (void)
 {
   long res = sysconf (_SC_IOV_MAX);
   if (res >= 0)
-    mhd_iov_max_ = res;
+    mhd_iov_max_ = (unsigned long) res;
 #if defined(IOV_MAX)
   else
     mhd_iov_max_ = IOV_MAX;
@@ -1399,7 +1399,6 @@ send_iov_nontls (struct MHD_Connection *connection,
                  bool push_data)
 {
   ssize_t res;
-  ssize_t total_sent;
   size_t items_to_send;
 #ifdef HAVE_SENDMSG
   struct msghdr msg;
@@ -1501,35 +1500,38 @@ send_iov_nontls (struct MHD_Connection *connection,
   }
 
   /* Some data has been sent */
-  total_sent = res;
-  /* Adjust the internal tracking information for the iovec to
-   * take this last send into account. */
-  while ((0 != res) && (r_iov->iov[r_iov->sent].iov_len <= (size_t) res))
+  if (1)
   {
-    res -= r_iov->iov[r_iov->sent].iov_len;
-    r_iov->sent++; /* The iov element has been completely sent */
-    mhd_assert ((r_iov->cnt > r_iov->sent) || (0 == res));
-  }
+    size_t track_sent = (size_t) res;
+    /* Adjust the internal tracking information for the iovec to
+     * take this last send into account. */
+    while ((0 != track_sent) && (r_iov->iov[r_iov->sent].iov_len <= track_sent))
+    {
+      track_sent -= r_iov->iov[r_iov->sent].iov_len;
+      r_iov->sent++; /* The iov element has been completely sent */
+      mhd_assert ((r_iov->cnt > r_iov->sent) || (0 == track_sent));
+    }
 
-  if (r_iov->cnt == r_iov->sent)
-    post_send_setopt (connection, true, push_data);
-  else
-  {
+    if (r_iov->cnt == r_iov->sent)
+      post_send_setopt (connection, true, push_data);
+    else
+    {
 #ifdef EPOLL_SUPPORT
-    connection->epoll_state &=
-      ~((enum MHD_EpollState) MHD_EPOLL_STATE_WRITE_READY);
+      connection->epoll_state &=
+        ~((enum MHD_EpollState) MHD_EPOLL_STATE_WRITE_READY);
 #endif /* EPOLL_SUPPORT */
-    if (0 != res)
-    {
-      mhd_assert (r_iov->cnt > r_iov->sent);
-      /* The last iov element has been partially sent */
-      r_iov->iov[r_iov->sent].iov_base =
-        (void *) ((uint8_t *) r_iov->iov[r_iov->sent].iov_base + (size_t) res);
-      r_iov->iov[r_iov->sent].iov_len -= (MHD_iov_size_) res;
+      if (0 != track_sent)
+      {
+        mhd_assert (r_iov->cnt > r_iov->sent);
+        /* The last iov element has been partially sent */
+        r_iov->iov[r_iov->sent].iov_base =
+          (void *) ((uint8_t *) r_iov->iov[r_iov->sent].iov_base + track_sent);
+        r_iov->iov[r_iov->sent].iov_len -= (MHD_iov_size_) track_sent;
+      }
     }
   }
 
-  return total_sent;
+  return res;
 }
 
 
@@ -1567,7 +1569,7 @@ send_iov_emu (struct MHD_Connection *connection,
   do
   {
     if ((size_t) SSIZE_MAX - total_sent < r_iov->iov[r_iov->sent].iov_len)
-      return total_sent; /* return value would overflow */
+      return (ssize_t) total_sent; /* return value would overflow */
 
     res = MHD_send_data_ (connection,
                           r_iov->iov[r_iov->sent].iov_base,
@@ -1580,7 +1582,7 @@ send_iov_emu (struct MHD_Connection *connection,
         return res; /* Nothing was sent, return result as is */
 
       if (MHD_ERR_AGAIN_ == res)
-        return total_sent; /* Some data has been sent, return the amount */
+        return (ssize_t) total_sent; /* Return the amount of the sent data */
 
       return res; /* Any kind of a hard error */
     }
@@ -1589,13 +1591,14 @@ send_iov_emu (struct MHD_Connection *connection,
 
     if (r_iov->iov[r_iov->sent].iov_len != (size_t) res)
     {
+      const size_t sent = (size_t) res;
       /* Incomplete buffer has been sent.
        * Adjust buffer of the last element. */
       r_iov->iov[r_iov->sent].iov_base =
-        (void *) ((uint8_t *) r_iov->iov[r_iov->sent].iov_base + (size_t) res);
-      r_iov->iov[r_iov->sent].iov_len -= res;
+        (void *) ((uint8_t *) r_iov->iov[r_iov->sent].iov_base + sent);
+      r_iov->iov[r_iov->sent].iov_len -= sent;
 
-      return total_sent;
+      return (ssize_t) total_sent;
     }
     /* The iov element has been completely sent */
     r_iov->sent++;
diff --git a/src/microhttpd/mhd_str.c b/src/microhttpd/mhd_str.c
index fdbed4f8..da60b18d 100644
--- a/src/microhttpd/mhd_str.c
+++ b/src/microhttpd/mhd_str.c
@@ -899,12 +899,12 @@ MHD_str_to_uint64_ (const char *str,
       return 0;
 
     res *= 10;
-    res += digit;
+    res += (unsigned int) digit;
     str++;
   } while (isasciidigit (*str));
 
   *out_val = res;
-  return str - start;
+  return (size_t) (str - start);
 }
 
 
@@ -944,7 +944,7 @@ MHD_str_to_uint64_n_ (const char *str,
       return 0;
 
     res *= 10;
-    res += digit;
+    res += (unsigned int) digit;
     i++;
   } while ( (i < maxlen) &&
             isasciidigit (str[i]) );
@@ -984,7 +984,7 @@ MHD_strx_to_uint32_ (const char *str,
                                                                % 16)) ) )
     {
       res *= 16;
-      res += digit;
+      res += (unsigned int) digit;
     }
     else
       return 0;
@@ -994,7 +994,7 @@ MHD_strx_to_uint32_ (const char *str,
 
   if (str - start > 0)
     *out_val = res;
-  return str - start;
+  return (size_t) (str - start);
 }
 
 
@@ -1032,7 +1032,7 @@ MHD_strx_to_uint32_n_ (const char *str,
       return 0;
 
     res *= 16;
-    res += digit;
+    res += (unsigned int) digit;
     i++;
   }
 
@@ -1071,7 +1071,7 @@ MHD_strx_to_uint64_ (const char *str,
                                                                % 16)) ) )
     {
       res *= 16;
-      res += digit;
+      res += (unsigned int) digit;
     }
     else
       return 0;
@@ -1081,7 +1081,7 @@ MHD_strx_to_uint64_ (const char *str,
 
   if (str - start > 0)
     *out_val = res;
-  return str - start;
+  return (size_t) (str - start);
 }
 
 
@@ -1119,7 +1119,7 @@ MHD_strx_to_uint64_n_ (const char *str,
       return 0;
 
     res *= 16;
-    res += digit;
+    res += (unsigned int) digit;
     i++;
   }
 
@@ -1178,7 +1178,7 @@ MHD_str_to_uvalue_n_ (const char *str,
       return 0;
 
     res *= base;
-    res += digit;
+    res += (unsigned int) digit;
     i++;
   }
 
@@ -1330,7 +1330,7 @@ MHD_uint8_to_str_pad (uint8_t val,
   }
   else
   {
-    buf[pos++] = '0' + digit;
+    buf[pos++] = '0' + (char) digit;
     val %= 100;
     min_digits = 2;
   }
@@ -1345,13 +1345,13 @@ MHD_uint8_to_str_pad (uint8_t val,
   }
   else
   {
-    buf[pos++] = '0' + digit;
+    buf[pos++] = '0' + (char) digit;
     val %= 10;
   }
 
   if (buf_size <= pos)
     return 0;
-  buf[pos++] = '0' + val;
+  buf[pos++] = '0' + (char) val;
   return pos;
 }
 
diff --git a/src/microhttpd/postprocessor.c b/src/microhttpd/postprocessor.c
index d32ecc22..39070334 100644
--- a/src/microhttpd/postprocessor.c
+++ b/src/microhttpd/postprocessor.c
@@ -367,20 +367,23 @@ process_value (struct MHD_PostProcessor *pp,
   if ( (NULL != last_escape) &&
        (((size_t) (value_end - last_escape)) < sizeof (pp->xbuf)) )
   {
-    pp->xbuf_pos = value_end - last_escape;
+    mhd_assert (value_end >= last_escape);
+    pp->xbuf_pos = (size_t) (value_end - last_escape);
     memcpy (pp->xbuf,
             last_escape,
-            value_end - last_escape);
+            (size_t) (value_end - last_escape));
     value_end = last_escape;
   }
   while ( (value_start != value_end) ||
           (pp->must_ikvi) ||
           (xoff > 0) )
   {
-    size_t delta = value_end - value_start;
+    size_t delta = (size_t) (value_end - value_start);
     bool cut = false;
     size_t clen = 0;
 
+    mhd_assert (value_end >= value_start);
+
     if (delta > XBUF_SIZE - xoff)
       delta = XBUF_SIZE - xoff;
     /* move (additional) input into processing buffer */
@@ -660,7 +663,8 @@ post_process_urlencoded (struct MHD_PostProcessor *pp,
       mhd_assert ((NULL != end_key) || (NULL == start_key));
       if (1)
       {
-        const size_t key_len = end_key - start_key;
+        const size_t key_len = (size_t) (end_key - start_key);
+        mhd_assert (end_key >= start_key);
         if (0 != key_len)
         {
           if ( (pp->buffer_pos + key_len >= pp->buffer_size) ||
@@ -725,7 +729,8 @@ post_process_urlencoded (struct MHD_PostProcessor *pp,
     mhd_assert ((PP_ProcessKey == pp->state) || (NULL != end_key));
     if (NULL == end_key)
       end_key = &post_data[poff];
-    key_len = end_key - start_key;
+    mhd_assert (end_key >= start_key);
+    key_len = (size_t) (end_key - start_key);
     mhd_assert (0 != key_len); /* it must be always non-zero here */
     if (pp->buffer_pos + key_len >= pp->buffer_size)
     {
@@ -854,13 +859,13 @@ find_boundary (struct MHD_PostProcessor *pp,
                      '-',
                      pp->buffer_pos);
       if (NULL == dash)
-        (*ioffptr) += pp->buffer_pos;  /* skip entire buffer */
+        (*ioffptr) += pp->buffer_pos;         /* skip entire buffer */
       else if (dash == buf)
-        (*ioffptr)++;                  /* at least skip one byte */
+        (*ioffptr)++;                         /* at least skip one byte */
       else
-        (*ioffptr) += dash - buf;      /* skip to first possible boundary */
+        (*ioffptr) += (size_t) (dash - buf);  /* skip to first possible boundary */
     }
-    return MHD_NO;                     /* expected boundary */
+    return MHD_NO;                            /* expected boundary */
   }
   /* remove boundary from buffer */
   (*ioffptr) += 2 + blen;
@@ -908,7 +913,7 @@ try_get_value (const char *buf,
     if (NULL == (endv = strchr (&spos[klen + 2],
                                 '\"')))
       return;                   /* no end-quote */
-    vlen = endv - spos - klen - 1;
+    vlen = (size_t) (endv - spos) - klen - 1;
     *destination = malloc (vlen);
     if (NULL == *destination)
       return;                   /* out of memory */
@@ -1037,7 +1042,7 @@ process_value_to_boundary (struct MHD_PostProcessor *pp,
         newline = pp->buffer_pos - 4;
         break;
       }
-      newline = r - buf;
+      newline = (size_t) (r - buf);
       if (0 == memcmp ("\r\n--",
                        &buf[newline],
                        4))
diff --git a/src/microhttpd/response.c b/src/microhttpd/response.c
index 47e28046..0a70c0f7 100644
--- a/src/microhttpd/response.c
+++ b/src/microhttpd/response.c
@@ -213,11 +213,11 @@ add_response_header_connection (struct MHD_Response *response,
   /** the length of the "Connection" key */
   static const size_t key_len =
     MHD_STATICSTR_LEN_ (MHD_HTTP_HEADER_CONNECTION);
-  size_t value_len;  /**< the length of the @a value */
+  size_t value_len; /**< the length of the @a value */
   size_t old_value_len; /**< the length of the existing "Connection" value */
-  size_t buf_size;   /**< the size of the buffer */
-  ssize_t norm_len;  /**< the length of the normalised value */
-  char *buf;         /**< the temporal buffer */
+  size_t buf_size;  /**< the size of the buffer */
+  size_t norm_len;  /**< the length of the normalised value */
+  char *buf;        /**< the temporal buffer */
   struct MHD_HTTP_Res_Header *hdr; /**< existing "Connection" header */
   bool value_has_close; /**< the @a value has "close" token */
   bool already_has_close; /**< existing "Connection" header has "close" token */
@@ -253,19 +253,27 @@ add_response_header_connection (struct MHD_Response *response,
   value_len = strlen (value);
   if (value_len >= SSIZE_MAX)
     return MHD_NO;
-  /* Additional space for normalisation and zero-termination*/
-  norm_len = (ssize_t) (value_len + value_len / 2 + 1);
+  /* Additional space for normalisation and zero-termination */
+  norm_len = value_len + value_len / 2 + 1;
   buf_size = old_value_len + (size_t) norm_len;
 
   buf = malloc (buf_size);
   if (NULL == buf)
     return MHD_NO;
-  /* Remove "close" token (if any), it will be moved to the front */
-  value_has_close = MHD_str_remove_token_caseless_ (value, value_len, "close",
-                                                    MHD_STATICSTR_LEN_ ( \
-                                                      "close"),
-                                                    buf + old_value_len,
-                                                    &norm_len);
+  if (1)
+  { /* local scope */
+    ssize_t norm_len_s = (ssize_t) norm_len;
+    /* Remove "close" token (if any), it will be moved to the front */
+    value_has_close = MHD_str_remove_token_caseless_ (value, value_len, "close",
+                                                      MHD_STATICSTR_LEN_ ( \
+                                                        "close"),
+                                                      buf + old_value_len,
+                                                      &norm_len_s);
+    mhd_assert (0 <= norm_len_s);
+    if (0 > norm_len_s)
+      norm_len = 0; /* Must never happen */
+    norm_len = (size_t) norm_len;
+  }
 #ifdef UPGRADE_SUPPORT
   if ( (NULL != response->upgrade_handler) && value_has_close)
   { /* The "close" token cannot be used with connection "upgrade" */
@@ -273,17 +281,10 @@ add_response_header_connection (struct MHD_Response *response,
     return MHD_NO;
   }
 #endif /* UPGRADE_SUPPORT */
-  mhd_assert (0 <= norm_len);
-  if (0 > norm_len)
-    norm_len = 0; /* Must never happen */
   if (0 != norm_len)
-  {
-    size_t len = norm_len;
-    MHD_str_remove_tokens_caseless_ (buf + old_value_len, &len,
+    MHD_str_remove_tokens_caseless_ (buf + old_value_len, &norm_len,
                                      "keep-alive",
                                      MHD_STATICSTR_LEN_ ("keep-alive"));
-    norm_len = (ssize_t) len;
-  }
   if (0 == norm_len)
   { /* New value is empty after normalisation */
     if (! value_has_close)
@@ -301,7 +302,7 @@ add_response_header_connection (struct MHD_Response *response,
   if (value_has_close && ! already_has_close)
   {
     /* Need to insert "close" token at the first position */
-    mhd_assert (buf_size >= old_value_len + (size_t) norm_len   \
+    mhd_assert (buf_size >= old_value_len + norm_len   \
                 + MHD_STATICSTR_LEN_ ("close, ") + 1);
     if (0 != norm_len)
       memmove (buf + MHD_STATICSTR_LEN_ ("close, ") + old_value_len,
@@ -333,7 +334,7 @@ add_response_header_connection (struct MHD_Response *response,
     mhd_assert ((value_has_close && ! already_has_close) ? \
                 (MHD_STATICSTR_LEN_ ("close, ") + old_value_len == pos) : \
                 (old_value_len == pos));
-    pos += (size_t) norm_len;
+    pos += norm_len;
   }
   mhd_assert (buf_size > pos);
   buf[pos] = 0; /* Null terminate the result */
@@ -1118,7 +1119,7 @@ MHD_create_response_from_fd_at_offset (size_t size,
 {
   return MHD_create_response_from_fd_at_offset64 (size,
                                                   fd,
-                                                  offset);
+                                                  (uint64_t) offset);
 }
 
 
@@ -1631,7 +1632,7 @@ MHD_create_response_from_iovec (const struct MHD_IoVec *iov,
     MHD_iovec_ *iov_copy;
     int num_copy_elements = i_cp;
 
-    iov_copy = MHD_calloc_ (num_copy_elements,
+    iov_copy = MHD_calloc_ ((size_t) num_copy_elements, \
                             sizeof(MHD_iovec_));
     if (NULL == iov_copy)
     {
@@ -1662,8 +1663,9 @@ MHD_create_response_from_iovec (const struct MHD_IoVec *iov,
       i_cp++;
     }
     mhd_assert (num_copy_elements == i_cp);
+    mhd_assert (0 <= i_cp);
     response->data_iov = iov_copy;
-    response->data_iovcnt = i_cp;
+    response->data_iovcnt = (unsigned int) i_cp;
   }
   return response;
 }