Check that note files open before reading them

This fixes the scenario where a note file referenced by a todo, event,
or appointment is modified from outside the program in such a way that
it cannot be opened by the program, resulting in a segmentation fault.

The least surprising way to proceed is to ignore the note.

Signed-off-by: Nicholas Johnson <nick@nicksphere.ch>
Signed-off-by: Lukas Fleischer <lfleischer@calcurse.org>

2 files changed, 13 insertions, 0 deletions

diff --git a/src/day.c b/src/day.c
index a86a91d..13149ea 100644
--- a/src/day.c
+++ b/src/day.c
@@ -634,6 +634,10 @@ void day_popup_item(struct day_item *day)
 
 			asprintf(&notepath, "%s%s", path_notes, day_item_get_note(day));
 			fp = fopen(notepath, "r");
+			if (fp == NULL) {
+				item_in_popup(NULL, NULL, day_item_get_mesg(day), _("Event:"));
+				return;
+			}
 			note_read_contents(note, note_size, fp);
 			fclose(fp);
 			mem_free(notepath);
@@ -661,6 +665,10 @@ void day_popup_item(struct day_item *day)
 
 			asprintf(&notepath, "%s%s", path_notes, day_item_get_note(day));
 			fp = fopen(notepath, "r");
+			if (fp == NULL) {
+				item_in_popup(a_st, a_end, day_item_get_mesg(day), _("Appointment:"));
+				return;
+			}
 			note_read_contents(note, note_size, fp);
 			fclose(fp);
 			mem_free(notepath);
diff --git a/src/ui-todo.c b/src/ui-todo.c
index b65b8d3..6fdd08f 100644
--- a/src/ui-todo.c
+++ b/src/ui-todo.c
@@ -327,6 +327,11 @@ void ui_todo_popup_item(void)
 
 		asprintf(&notepath, "%s%s", path_notes, item->note);
 		fp = fopen(notepath, "r");
+		if (fp == NULL) {
+			item_in_popup(NULL, NULL, item->mesg, _("TODO:"));
+			return;
+		}
+
 		note_read_contents(note, note_size, fp);
 		fclose(fp);
 		mem_free(notepath);