NULL pointer vs bool "false" confusion

there are some places in the mpd-0.17.4 sources where a "false" is
used instead of a NULL pointer.

src/conf.c

@@ -317,7 +317,7 @@ config_read_block(FILE *fp, int *count, char *string, GError **error_r)
 				g_set_error(error_r, config_quark(), 0,
 					    "line %i: Unknown tokens after '}'",
 					    *count);
-				return false;
+				return NULL;
 			}
 
 			return ret;

src/song_update.c

@@ -187,7 +187,7 @@ song_file_update_inarchive(struct song *song)
 	if (suffix == NULL)
 		return false;
 
-	plugin = decoder_plugin_from_suffix(suffix, false);
+	plugin = decoder_plugin_from_suffix(suffix, NULL);
 	if (plugin == NULL)
 		return false;
 

src/update_song.c

@@ -104,7 +104,7 @@ update_song_file(struct directory *directory,
 		 const struct stat *st)
 {
 	const struct decoder_plugin *plugin =
-		decoder_plugin_from_suffix(suffix, false);
+		decoder_plugin_from_suffix(suffix, NULL);
 	if (plugin == NULL)
 		return false;