From: Carl Hetherington <cth@carlh.net>
Date: Wed, 29 Mar 2023 23:25:25 +0000 (+0200)
Subject: Use CURLOPT_NOSIGNAL to fix crashes on update check (#2495).
X-Git-Tag: v2.16.51~1
X-Git-Url: https://git.carlh.net/gitweb/?p=dcpomatic.git;a=commitdiff_plain;h=0fab37d3b61eb150b3de4a4000b8156e6e53574b

Use CURLOPT_NOSIGNAL to fix crashes on update check (#2495).

Without this, it's possible to come back from curl_easy_perform
in a different thread to the one that it was called from (in the case
of an error).

As I understand it, this happens because a signal handler is called
(from a different thread) and CURLOPT_NOSIGNAL stops this from
happening.
---

diff --git a/src/lib/update_checker.cc b/src/lib/update_checker.cc
index 2c2e23be1..3897b81d8 100644
--- a/src/lib/update_checker.cc
+++ b/src/lib/update_checker.cc
@@ -66,6 +66,7 @@ UpdateChecker::UpdateChecker ()
 	curl_easy_setopt (_curl, CURLOPT_WRITEFUNCTION, write_callback_wrapper);
 	curl_easy_setopt (_curl, CURLOPT_WRITEDATA, this);
 	curl_easy_setopt (_curl, CURLOPT_TIMEOUT, 20);
+	curl_easy_setopt (_curl, CURLOPT_NOSIGNAL, 1L);
 
 	string const agent = "dcpomatic/" + string (dcpomatic_version);
 	curl_easy_setopt (_curl, CURLOPT_USERAGENT, agent.c_str ());