Guard against NULL outbind entry in DO statement parameter setup

[Aias00]

Summary

Fixes #1617: in the DO-statement parameter setup of IvyStmtExecute (src/interfaces/libpq/ivy-exec.c), the inner loop searches outbind for info->position == i + 1 and then dereferences info unconditionally. If the caller bound non-contiguous positions (e.g. 1 and 3, skipping 2), info is NULL and info->dtype crashes the client process.

The fix reports "outbind position not found" and cleans up (paramTypes + query_buf) before returning 0, matching the error style of the same function.

Test plan

• make -C src/interfaces/libpq ivy-exec.o compiles cleanly.
• Manual: bind positions 1 and 3 of a 3-placeholder statement and execute a DO statement — the client now gets an error instead of crashing.

Summary by CodeRabbit

• Bug Fixes
  • Added validation for missing output parameter bindings.
  • Improved error handling to prevent failures when an output parameter has no corresponding bind entry.

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

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Review profile: CHILL

Plan: Pro Plus

Run ID: dbcae688-a4c3-46a3-97e5-a8c287082505

📥 Commits

Reviewing files that changed from the base of the PR and between c3529ba and a80109d.

📒 Files selected for processing (1)

• src/interfaces/libpq/ivy-exec.c

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📝 Walkthrough

Walkthrough

IvyHandleDostmt now detects missing OUT-bind entries before dereferencing them. It reports an error, releases allocated resources, and returns failure.

Changes

OUT-bind validation

Layer / File(s)	Summary
Validate missing OUT-bind positions src/interfaces/libpq/ivy-exec.c	IvyHandleDostmt checks for a matching OUT-bind entry. When none exists, it records an error, frees paramTypes, destroys query_buf, and returns 0.

Estimated code review effort: 2 (Simple) | ~10 minutes

Merge Risk: ⚪ Minimal · up to a8010

This localized fix prevents a client crash when DO-statement parameter positions are non-contiguous and returns an error instead; no actionable merge-blocking risk remains after normal checks and review.

🚥 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	The title clearly describes the NULL outbind-entry guard added for DO statement parameter setup.
Linked Issues check	✅ Passed	The change detects missing outbind entries, reports an error, cleans up resources, and prevents the NULL dereference required by issue #1617.
Out of Scope Changes check	✅ Passed	The changes are limited to validation and cleanup for the linked NULL dereference issue.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.

✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests

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[NotHimmel]

Thanks for the report and PR, could you confirm how it was found and provide a concrete reproduction?

[Aias00]

Closing per the discussion in #1617 - the NULL deref is real but only reachable when a C client binds non-contiguous positions via IvyBindByPos (an unusual pattern no in-tree code produces); impact is a client-process crash only. Happy to resubmit the one-line guard as a focused PR if a maintainer wants it.