Reset connection deadline before connection is released

[jkaflik]

Summary

It's not well well-thought-out fix attempt for #1607.

Requires deep dive into edge cases.

Checklist

Delete items not relevant to your PR:

• Unit and integration tests covering the common scenarios were added
• A human-readable description of the changes was provided to include in CHANGELOG
• For significant changes, documentation in https://github.com/ClickHouse/clickhouse-docs was updated with further explanations or tutorials

[Copilot]

Pull Request Overview

This PR adjusts when the connection deadline is cleared by removing the early defer reset and instead resetting the deadline inside the streaming goroutine just before the connection is released.

• Drop deferred reset of c.conn.SetDeadline immediately after setting context deadline.
• Add explicit c.conn.SetDeadline(time.Time{}) in the goroutine after both streams close.
• Shift responsibility for clearing the deadline to just before release.

[Copilot]

If a deadline was set on the connection, it isn't cleared when sendQuery returns an error, which can leave a stale deadline on subsequent operations. Consider using defer immediately after setting the deadline or explicitly clearing it in this error path.

Suggested change

	if err = c.sendQuery(body, &options); err != nil {
	if err = c.sendQuery(body, &options); err != nil {
	c.conn.SetDeadline(time.Time{}) // Clear stale deadline

[Copilot]

This unconditional reset will clear any pre-existing deadlines—even if none were set for this query—which may unintentionally override other timeouts. Track whether you applied a context deadline and guard the reset accordingly.

Suggested change

	c.conn.SetDeadline(time.Time{})
	if _, ok := ctx.Deadline(); !ok {
	c.conn.SetDeadline(time.Time{})
	}

[GeorgeMac]

I think we might need to do this for SetReadDeadline too. As the SetDeadline is an override on the context. I am unsure what we're using exactly in our case.

p.s. thanks for jumping on this so quickly!