fix(ndk): Create outbox directory before writing crash envelopes

[runningcode]

Summary

On Android, the NDK layer writes crash/native envelopes through a custom transport (send_envelope in ndk/lib/src/main/jni/sentry.c) that targets the head SDK's outbox path. However:

• Native sentry_init only creates its own database directory, which the JNI layer derives as .sentry-native — a sibling of the outbox, not the outbox itself (sentry.c:417-429).
• The transport writes the envelope with sentry_envelope_write_to_file, which ultimately open(..., O_CREAT)s the file but does not create parent directories.

So if the outbox directory does not exist when an envelope is flushed, the write fails silently (only a SENTRY_WARN) and the crash report is lost. Today this works only because head SDKs (and the sample's MainActivity.setupOutboxFolder()) create the outbox eagerly.

This becomes a real risk as head SDKs move to lazy outbox/cache creation (e.g. getsentry/sentry-java#5792): a native envelope written before the head SDK's lazy creator runs would be dropped.

Change

Create the outbox directory in the transport before each write, using sentry__path_create_dir_all — the same recursive, self-healing pattern every other sentry-native write path (cache, external) already uses. This makes native self-sufficient and lets head SDKs defer outbox creation without dropping native crash envelopes.

Notes

• The internal sentry__path_* symbols are exported via the sentry_* glob in src/exports.map and are already reached from this JNI file via extern (e.g. sentry__value_from_json, sentry__backend_preload), so this follows the established pattern.

🤖 Generated with Claude Code

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 75.75%. Comparing base (8ef6876) to head (f212c73).
⚠️ Report is 3 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #1889      +/-   ##
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+ Coverage   75.42%   75.75%   +0.32%     
==========================================
  Files          92       92              
  Lines       21599    21966     +367     
  Branches     3807     3914     +107     
==========================================
+ Hits        16291    16640     +349     
- Misses       4438     4442       +4     
- Partials      870      884      +14     

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[jpnurmi]

sorry about this, btw. it's not that easy to access sentry-native internals. 🙂 we probably don't want to expose sentry_path at this point, unfortunately...