fix crash when SSL_CTX_new fails

[Zhouyang Jia <jiazhouyang09 gmail com>]

Hi,

I'm new to Balsa, I analyzed the source code and found a potential bug that may cause crash.

In balsa-2.5.3/libbalsa/imap/imap-tls.c:174:26, if "SSL_CTX_new" failed to initialize the SSL context, "SSL_CTX_set_options" would cause a crash since "global_ssl_context" is null.

I think it's unsafe to assume that the library function would be correct. It would be better if we could handle the error properly.

Attached please find the patch against version balsa-2.5.3. Hopefully, it can solve this potential bug.

Best,

Zhouyang

Attachment: balsa-2.5.3.patch
Description: Binary data