Treat watch dir errors and fix various things

Verity if dmon_watch returns an error.

Add a check if an added file for which we received a create event is
ignored based on the user's config.

Add some explanatory comments in the code.

data/core/init.lua

@@ -336,7 +336,7 @@ local function project_scan_add_file(watch_id, filepath)
       project_dir_entry = core.project_directories[i]
     end
   end
-  if not project_dir_entry then return end
+  if not project_dir_entry or common.match_pattern(filepath, config.ignore_files) then return end
   local size_limit = config.file_size_limit * 10e5
   local fileinfo = get_project_file_info(project_dir_entry.name, PATHSEP .. filepath, size_limit)
   local index, match = file_search(project_dir_entry.files, fileinfo)

src/api/system.c

@@ -660,20 +660,11 @@ static int f_set_window_opacity(lua_State *L) {
   return 1;
 }
 
-static void watch_callback(dmon_watch_id watch_id, dmon_action action, const char* rootdir,
-  const char* filepath, const char* oldfilepath, void* user)
-{
-  (void)(user);
-  (void)(rootdir);
-  dirmonitor_push_event(watch_id, action, filepath, oldfilepath);
-}
-
 static int f_watch_dir(lua_State *L) {
   const char *path = luaL_checkstring(L, 1);
-  fprintf(stderr, "DEBUG: watching dir: %s\n", path); fflush(stderr);
-  dmon_watch_id watch_id = dmon_watch(path, watch_callback, DMON_WATCHFLAGS_RECURSIVE, NULL);
+  dmon_watch_id watch_id = dmon_watch(path, dirmonitor_watch_callback, DMON_WATCHFLAGS_RECURSIVE, NULL);
+  if (watch_id.id == 0) { luaL_error(L, "directory monitoring watch failed"); }
   lua_pushnumber(L, watch_id.id);
-  // FIXME: we ignore if there is an error.
   return 1;
 }
 
@@ -683,7 +674,8 @@ static int f_watch_dir(lua_State *L) {
 #define PATHSEP '/'
 #endif
 
-
+/* Special purpose filepath compare function. Corresponds to the
+   order used in the TreeView view of the project's files. */
 static int f_path_compare(lua_State *L) {
   const char *path1 = luaL_checkstring(L, 1);
   const char *type1_s = luaL_checkstring(L, 2);
@@ -692,20 +684,25 @@ static int f_path_compare(lua_State *L) {
   const int len1 = strlen(path1), len2 = strlen(path2);
   int type1 = strcmp(type1_s, "dir") != 0;
   int type2 = strcmp(type2_s, "dir") != 0;
+  /* Find the index of the common part of the path. */
   int i;
   for (i = 0; i < len1 && i < len2; i++) {
     if (path1[i] != path2[i]) break;
   }
+  /* If a path separator is present in the name after the common part we consider
+     the entry like a directory. */
   if (strchr(path1 + i, PATHSEP)) {
     type1 = 0;
   }
   if (strchr(path2 + i, PATHSEP)) {
     type2 = 0;
   }
+  /* If types are different "dir" types comes before "file" types. */
   if (type1 != type2) {
     lua_pushboolean(L, type1 < type2);
     return 1;
   }
+  /* If types are the same compare the files' path alphabetically. */
   lua_pushboolean(L, strcmp(path1 + i, path2 + i) < 0);
   return 1;
 }

src/dirmonitor.c

@@ -11,6 +11,8 @@
 static void send_sdl_event(dmon_watch_id watch_id, dmon_action action, const char *filepath) {
   SDL_Event ev;
   const int size = strlen(filepath) + 1;
+  /* The string allocated below should be deallocated as soon as the event is
+     treated in the SDL main loop. */
   char *new_filepath = malloc(size);
   if (!new_filepath) return;
   memcpy(new_filepath, filepath, size);
@@ -23,7 +25,6 @@ static void send_sdl_event(dmon_watch_id watch_id, dmon_action action, const cha
 #endif
   SDL_zero(ev);
   ev.type = SDL_USEREVENT;
-  fprintf(stderr, "DEBUG: send watch_id: %d action; %d\n", watch_id.id, action); fflush(stderr);
   ev.user.code = ((watch_id.id & 0xffff) << 16) | (action & 0xffff);
   ev.user.data1 = new_filepath;
   SDL_PushEvent(&ev);
@@ -31,7 +32,8 @@ static void send_sdl_event(dmon_watch_id watch_id, dmon_action action, const cha
 
 void dirmonitor_init() {
   dmon_init();
-  /* FIXME: not needed ? */
+  /* In theory we should register our user event but since we
+     have just one type of user event this is not really needed. */
   /* sdl_dmon_event_type = SDL_RegisterEvents(1); */
 }
 
@@ -39,9 +41,11 @@ void dirmonitor_deinit() {
   dmon_deinit();
 }
 
-void dirmonitor_push_event(dmon_watch_id watch_id, dmon_action action, const char *filepath,
-  const char *oldfilepath)
+void dirmonitor_watch_callback(dmon_watch_id watch_id, dmon_action action, const char *rootdir,
+  const char *filepath, const char *oldfilepath, void *user)
 {
+  (void) rootdir;
+  (void) user;
   switch (action) {
   case DMON_ACTION_MOVE:
     send_sdl_event(watch_id, DMON_ACTION_DELETE, oldfilepath);

src/dirmonitor.h

@@ -7,8 +7,8 @@
 
 void dirmonitor_init();
 void dirmonitor_deinit();
-void dirmonitor_push_event(dmon_watch_id watch_id, dmon_action action, const char *filepath,
-  const char *oldfilepath);
+void dirmonitor_watch_callback(dmon_watch_id watch_id, dmon_action action, const char *rootdir,
+  const char *filepath, const char *oldfilepath, void *user);
 
 #endif