fix(core): Only consider exception mechanism when updating session status from event with exceptions

[Lms24]

This PR fixes an oversight in our session update logic when we update the SDK's session status while processing an error event. Previously, we'd always set status: 'crashed' as soon as the top-level event.level field was set to 'fatal' (added in #15072). However, this disregarded the case where the level was initially 'fatal' but later on the SDK or users decided to set the event.exceptions.values[i].mechanism.handled field to true.

Simplest reproduction:

Sentry.captureException(new Error('test'), { captureContext: { level: 'fatal' } });

This PR changes the update logic to only look at the event mechanisms if the event contained exceptions. I think this is still compatible with #15072 because the PR suggests we only care about event.level === 'fatal' if no exceptions are on the event. But I'd appreciate a second pair of eyes on this (cc @timfish).

[github-actions]

size-limit report 📦

Path	Size	% Change	Change
@sentry/browser	24.59 kB	-0.01%	-2 B 🔽
@sentry/browser - with treeshaking flags	23.08 kB	+0.01%	+1 B 🔺
@sentry/browser (incl. Tracing)	41.23 kB	+0.02%	+5 B 🔺
@sentry/browser (incl. Tracing, Profiling)	45.5 kB	+0.01%	+1 B 🔺
@sentry/browser (incl. Tracing, Replay)	79.7 kB	+0.01%	+3 B 🔺
@sentry/browser (incl. Tracing, Replay) - with treeshaking flags	69.38 kB	+0.01%	+4 B 🔺
@sentry/browser (incl. Tracing, Replay with Canvas)	84.4 kB	+0.01%	+4 B 🔺
@sentry/browser (incl. Tracing, Replay, Feedback)	96.57 kB	-	-
@sentry/browser (incl. Feedback)	41.27 kB	-0.01%	-1 B 🔽
@sentry/browser (incl. sendFeedback)	29.26 kB	-0.01%	-1 B 🔽
@sentry/browser (incl. FeedbackAsync)	34.19 kB	-0.01%	-1 B 🔽
@sentry/react	26.29 kB	+0.01%	+1 B 🔺
@sentry/react (incl. Tracing)	43.21 kB	+0.01%	+2 B 🔺
@sentry/vue	29.07 kB	-0.01%	-2 B 🔽
@sentry/vue (incl. Tracing)	43 kB	+0.01%	+4 B 🔺
@sentry/svelte	24.6 kB	-0.02%	-3 B 🔽
CDN Bundle	26.89 kB	+0.02%	+4 B 🔺
CDN Bundle (incl. Tracing)	41.78 kB	+0.02%	+5 B 🔺
CDN Bundle (incl. Tracing, Replay)	78.3 kB	+0.01%	+5 B 🔺
CDN Bundle (incl. Tracing, Replay, Feedback)	83.78 kB	+0.01%	+5 B 🔺
CDN Bundle - uncompressed	78.84 kB	-0.01%	-7 B 🔽
CDN Bundle (incl. Tracing) - uncompressed	123.96 kB	-0.01%	-7 B 🔽
CDN Bundle (incl. Tracing, Replay) - uncompressed	239.99 kB	-0.01%	-7 B 🔽
CDN Bundle (incl. Tracing, Replay, Feedback) - uncompressed	252.75 kB	-0.01%	-7 B 🔽
@sentry/nextjs (client)	45.31 kB	+0.01%	+2 B 🔺
@sentry/sveltekit (client)	41.61 kB	+0.01%	+4 B 🔺
@sentry/node-core	50.76 kB	+0.01%	+4 B 🔺
@sentry/node	157.84 kB	+0.01%	+2 B 🔺
@sentry/node - without tracing	92.64 kB	+0.01%	+5 B 🔺
@sentry/aws-serverless	106.41 kB	+0.01%	+3 B 🔺

View base workflow run

[github-actions]

node-overhead report 🧳

Note: This is a synthetic benchmark with a minimal express app and does not necessarily reflect the real-world performance impact in an application.

Scenario	Requests/s	% of Baseline	Prev. Requests/s	Change %
GET Baseline	9,117	-	8,962	+2%
GET With Sentry	1,394	15%	1,428	-2%
GET With Sentry (error only)	6,031	66%	6,119	-1%
POST Baseline	1,198	-	1,212	-1%
POST With Sentry	497	41%	528	-6%
POST With Sentry (error only)	1,037	87%	1,066	-3%
MYSQL Baseline	3,240	-	3,357	-3%
MYSQL With Sentry	423	13%	509	-17%
MYSQL With Sentry (error only)	2,637	81%	2,759	-4%

View base workflow run