Replace qsort() with mutt_qsort_r()

[flatcap]

NeoMutt uses qsort() to sort lots of data.
It's quick, but some sorting requires extra data, which means global variables.

qsort_r() is an improved version that takes a data parameter, but it's not consistent across all platforms.

mutt_qsort_r() is a wrapper that hides the implementation details.

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Replace qsort() with mutt_qsort_r()

Below is a list of all the uses of qsort(), and their callback functions, including some used in ARRAY_SORT().

Every callback function needs to be checked for:

• Global variables
  e.g. static bool SbSortReverse = false;
• Config variables
  Lookups are quick, but they should only be done once

commands.c:818:5: envlist_sort()
complete/helpers.c:390:5: label_sort()
config/subset.c:94:3: elem_list_sort()
imap/imap.c:1570:3: imap_sort_email_uid()
maildir/maildir.c:234:7: maildir_sort_flags()
ncrypt/dlg_gpgme.c:735:5: crypt_compare_address_qsort(), crypt_compare_date_qsort(), crypt_compare_keyid_qsort(), crypt_compare_trust_qsort()
ncrypt/dlg_pgp.c:658:5: pgp_compare_address_qsort(), pgp_compare_date_qsort(), pgp_compare_keyid_qsort(), pgp_compare_trust_qsort()
alias/sort.c:175:3: alias_sort_address(), alias_sort_name(), alias_sort_name(), alias_sort_unsort()
browser/sort.c:214:3: browser_compare()
core/command.c:59:3: commands_sort()
imap/imap.c:1385:5: imap_sort_uid()
imap/imap.c:1485:5: imap_sort_uid()
imap/message.c:1653:3: imap_sort_uid()
maildir/maildir.c:592:3: maildir_sort_inode()
maildir/mh.c:674:5: mh_sort_path()
sidebar/sort.c:205:3: sb_sort_count(), sb_sort_desc(), sb_sort_flagged(), sb_sort_order(), sb_sort_path(), sb_sort_unread()

[roccoblues]

Do you want to replace all occurences or only the ones that actually would use the data parameter? For consistency it would probably be better to replace all?

[flatcap]

Yes, I think replacing all would be best

[roccoblues]

I can tackle this. Started here: #3953.

[flatcap]

Finished in: 02bd135