Program crashes when destructing "SimpleMail::MimeMessage" after calling "SimpleMail::MimeMessage::addPart"

[DxGrumpzz]

I have the following 3 lines in a function:

SimpleMail::MimeText text;
SimpleMail::MimeMessage message;
message.addPart(&text);

When the function exists, the program crashes as soon as it gets to the destruction of SimpleMail::MimeText. If I remove the line message.addPart(&text);, it works "fine".

I tried using the (blocking) code from the readme, and the demos. But both have the same problem.

This is the error I'm getting:

*** Error in `[Project path]': double free or corruption (out): 0x00007fffb0eff300 ***
======= Backtrace: =========
/lib/x86_64-linux-gnu/libc.so.6(+0x777f5)[0x7f57002117f5]
/lib/x86_64-linux-gnu/libc.so.6(+0x8038a)[0x7f570021a38a]
/lib/x86_64-linux-gnu/libc.so.6(cfree+0x4c)[0x7f570021e58c]
/usr/lib/x86_64-linux-gnu/libSimpleMail2Qt5.so.0(_ZN10SimpleMail8MimeTextD0Ev+0x24)[0x7f570126d47c]
/usr/lib/x86_64-linux-gnu/libSimpleMail2Qt5.so.0(+0x13f19)[0x7f5701269f19]
/usr/lib/x86_64-linux-gnu/libSimpleMail2Qt5.so.0(+0x13bf8)[0x7f5701269bf8]
/usr/lib/x86_64-linux-gnu/libSimpleMail2Qt5.so.0(+0x13554)[0x7f5701269554]
/usr/lib/x86_64-linux-gnu/libSimpleMail2Qt5.so.0(+0x135a0)[0x7f57012695a0]
/usr/lib/x86_64-linux-gnu/libSimpleMail2Qt5.so.0(+0x15f4b)[0x7f570126bf4b]
/usr/lib/x86_64-linux-gnu/libSimpleMail2Qt5.so.0(_ZN10SimpleMail8MimePartD1Ev+0x2e)[0x7f570126a3c2]
/usr/lib/x86_64-linux-gnu/libSimpleMail2Qt5.so.0(_ZN10SimpleMail13MimeMultiPartD1Ev+0x2a)[0x7f57012691b8]
/usr/lib/x86_64-linux-gnu/libSimpleMail2Qt5.so.0(_ZN10SimpleMail13MimeMultiPartD0Ev+0x18)[0x7f57012691e8]
/usr/lib/x86_64-linux-gnu/libSimpleMail2Qt5.so.0(+0xeaac)[0x7f5701264aac]
/usr/lib/x86_64-linux-gnu/libSimpleMail2Qt5.so.0(+0x102af)[0x7f57012662af]
/usr/lib/x86_64-linux-gnu/libSimpleMail2Qt5.so.0(_ZN10SimpleMail11MimeMessageD1Ev+0x2e)[0x7f5701263516]
[Project path][0x4040dc]
/lib/x86_64-linux-gnu/libc.so.6(__libc_start_main+0xf0)[0x7f57001ba840]
[Project path][0x402399]
...

(There's a section about Memory maps, it's very long, so I'm not sure if I should include it yet)

I'm using QT 5.11.1, Ubuntu 16.04, and GCC 5.4.0

[dantti]

addPart() expects an object allocated on the heap not stack, it will take ownership

[DxGrumpzz]

In the examples, and demos you have that exact code, is that intentional? Also, it seems kinda wasteful to allocate the heap. Is there a way to disable "ownership"?

[dantti]

if you look at the async examples it's on the heap https://github.com/cutelyst/simple-mail/blob/a7fd7f756ce8d2081607299f09c908f1e39e762a/README.md?plain=1#L53 How else can it live to be processed later when doing it async?

[DxGrumpzz]

Why would SimpleMail::MimeMessage take ownership of SimpleMail::MimeText when working in non async context? Your blocking examples show the "exact" code I have.

https://github.com/cutelyst/simple-mail/blob/a7fd7f756ce8d2081607299f09c908f1e39e762a/README.md?plain=1#L94-L106

How else can it live to be processed later when doing it async?

Can't argue with that, in an async context. But I'm using blocking code, I don't need async. I think the fix is very simple, just add something like an isAsync flag or something

[dantti]

Why would SimpleMail::MimeMessage take ownership of SimpleMail::MimeText when working in non async context?

Because it's nearly the same API and was created like this in the past, I also don't care much about the blocking one right now.

[dantti]

V3 API now uses std::shared_ptr, usage should be clearer