connection close tweaks

[icing]

• connclose/streamclose/connkeep() remove description string that was never used anywhere. Add trace statements where reasons for closing were not already traced and maybe not obvious.
• multi_remove_handle: only lookup former connection in pool when transfer is set to connect only
• test1554: adapt expectations now that pool is less often locked

[Copilot]

Pull request overview

This PR refactors curl’s internal connection/stream close/keep signaling by removing the (previously unused) “reason” string plumbing from connclose/streamclose/connkeep() and adding targeted trace output where close decisions might otherwise be unclear. It also adjusts multi-handle removal behavior for CONNECT_ONLY transfers and updates a debug test expectation to match reduced pool-lock activity.

Changes:

• Simplify connection control APIs: replace connclose(conn, "reason")/streamclose(conn, "reason")/connkeep(conn, "reason") with single-argument macros and a simplified Curl_conncontrol() signature.
• Tweak multi removal and pending scheduling: rename process_pending_handles() → multi_schedule_pending() and adjust Curl_multi_remove_handle() logic around CONNECT_ONLY.
• Update test1554 expectations due to less frequent CONNECT pool locking.

Reviewed changes

Copilot reviewed 26 out of 26 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
tests/data/test1554	Updates expected CONNECT lock/unlock trace output to match reduced locking.
lib/vssh/libssh2.c	Drops unused connclose reason string usage for SSH session cleanup.
lib/vssh/libssh.c	Drops unused connclose reason string usage for SSH session cleanup.
lib/vquic/cf-quiche.c	Removes connclose reason string for HTTP/3 refused-stream retry path.
lib/vquic/cf-ngtcp2.c	Removes connclose reason string for HTTP/3 refused-stream retry path.
lib/vquic/cf-ngtcp2-proxy.c	Removes connclose reason string for HTTP/3 refused-stream retry path.
lib/transfer.c	Removes connclose reason string on retry path.
lib/tftp.c	Removes connclose reason string for TFTP non-reuse policy.
lib/smtp.c	Adds trace before marking connection close on error; removes reason string.
lib/smb.c	Adds trace before marking connection close on SMB errors; removes reason strings.
lib/sendf.c	Removes stream/conn close reason strings in write-path error handling.
lib/pop3.c	Adds trace before marking connection close on error; removes reason string.
lib/multi.c	Renames pending scheduler function and adjusts connect-only removal handling; removes reason strings.
lib/mqtt.c	Removes connclose reason string on TLS connection failure path.
lib/ldap.c	Removes connclose reason string for LDAP always-non-reuse behavior.
lib/imap.c	Adds trace before marking connection close on error; removes reason string.
lib/http2.c	Adds/adjusts trace around close decisions; removes connclose reason strings.
lib/http.c	Removes reason strings from keep/close calls; adds trace in one close case.
lib/gopher.c	Removes connclose reason string on TLS connection failure path.
lib/ftp.c	Refactors helper signature and adds trace in error-close path; removes reason strings.
lib/easy.c	Simplifies connect-only cleanup by terminating the detached connection directly.
lib/connect.h	Renames control constants and collapses macros to single-argument forms; updates Curl_conncontrol signature.
lib/connect.c	Updates Curl_getconnectinfo() behavior and implements simplified Curl_conncontrol().
lib/conncache.h	Removes Curl_cpool_do_by_id() declaration (no longer used).
lib/conncache.c	Removes Curl_cpool_do_by_id() implementation (no longer used).
lib/cfilters.c	Makes Curl_conn_is_multiplex() null-safe and simplifies iteration.

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.