NimBLEAttValue.cpp - preserve capacity after realloc failure

[chmorgan]

NimBLEAttValue::append advanced m_capacity immediately after calling realloc. If realloc failed, the original buffer remained allocated but the object advertised a larger capacity than it actually owned. A later append could then skip reallocation and copy past the end of the allocation.

Track whether the append actually needs growth and only update m_capacity after the realloc result passes the null check. Appends that fit the existing allocation leave capacity unchanged; failed growth preserves the old capacity invariant.

Summary by CodeRabbit

• Bug Fixes
  • Improved data append behavior to better handle memory allocation failures.
  • Prevented internal capacity values from being updated when an expansion attempt fails, keeping state consistent and avoiding incorrect size reporting after errors.

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: Organization UI

Review profile: CHILL

Plan: Pro

Run ID: eac25d12-9551-4012-a88f-78f3b2984975

📥 Commits

Reviewing files that changed from the base of the PR and between 657583a and ede097a.

📒 Files selected for processing (1)

• src/NimBLEAttValue.cpp

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📝 Walkthrough

Walkthrough

Arr, this here PR patches up the NimBLEAttValue::append method, matey! It adds a grow flag to guide when reallocation be needed, and shifts the m_capacity update to only happen after realloc be a success, avoidin' a false capacity count when the reallocation fails.

Changes

AttValue Append Reallocation Fix

Layer / File(s)	Summary
Guard capacity update on realloc success src/NimBLEAttValue.cpp	Introduces a grow condition to control reallocation, and moves the m_capacity update so it only fires after realloc succeeds, keepin' the ship's hold accurate even when allocation fails.

Estimated code review effort: 1 (Trivial) | ~5 minutes

Poem

Yarrr, the buffer grows with care,
No false capacity in the air,
realloc succeeds, then we record,
A tighter ship, this rabbit's aboard! 🏴‍☠️🐇
Set sail, the code be shipshape now!

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	Arrr, the title clearly describes the main fix in NimBLEAttValue.cpp.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests

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