fix(ftb-tmux-popup): strip --tmux/--popup from FZF_DEFAULT_OPTS

[HaleTom]

Fixes #587

Problem

ftb-tmux-popup (lib/ftb-tmux-popup:27) only strips --height*/--layout* from fzf_opts. With zstyle ':fzf-tab:*' use-fzf-default-opts yes and export FZF_DEFAULT_OPTS='--tmux' (or --popup), the popup does a nested popup: outer tmux popup -E (from ftb-tmux-popup) + inner fzf --tmux popup. Result: popup flashes and disappears, inserting the query text instead of showing matches.

History: #455 reported --tmux in FZF_DEFAULT_OPTS breaks ftb-tmux-popup. #509 fixed it by propagating FZF_DEFAULT_OPTS into the popup (01dad759 changed FZF_DEFAULT_OPTS='' → FZF_DEFAULT_OPTS=${(qq)FZF_DEFAULT_OPTS}), which re-exposes the nested-popup case.

Fix

Strip --tmux/--popup (bare and =value forms) from the FZF_DEFAULT_OPTS env value passed to fzf inside the popup. Keep --height/--layout and all other opts.

# ${array:#pattern} filters the array as a whole and drops matching elements.
local -a _ftb_fdo_opts=(${(z)FZF_DEFAULT_OPTS})
local _ftb_fdo=${(j: :)_ftb_fdo_opts:#--(tmux|popup)*}

Note: filtering fzf_opts is NOT sufficient — fzf-tab's own fzf_opts never contains --tmux/--popup; the nesting comes from the FZF_DEFAULT_OPTS env propagated into the popup script (upstream #509). The env must be filtered.

Tests

21 new ztst cases in test/ftb-tmux-popup.ztst covering:

• bare --tmux, --popup
• --tmux=center,50%, --popup=bottom,30%
• mixed with --height=40% --color=fg:1 (others kept)
• bare --tmux does not eat the next arg
• empty input
• no tmux/popup untouched
• --popup= stripped among others
• --height 40% separate-arg kept, --tmux stripped
• both --tmux and --popup stripped
• both =value forms stripped
• tmux/popup at ends, middle kept
• height/layout kept, tmux= stripped
• all four forms stripped
• stripped result has zero elements (no '' placeholder) — via $#_r on (z)-split result
• kept args round-trip through %q unchanged
• quoted arg with space (--'has space') stays one element after (z) split; %q round-trips as --\'has space\' proving no '' placeholder is introduced

Verified: zsh +Z -f ./test/ztst.zsh test/ftb-tmux-popup.ztst → all tests successful. Existing test/fzftab.ztst still passes.

Verification

Minimal zshrc + tmux 3.7b with attached client:

• Before: ls <TAB> → popup flashes and disappears; buffer becomes ls ls (query text inserted, no match list).
• After: popup stays open, env FZF_DEFAULT_OPTS='' in generated script.

[HaleTom]

Two incidental test-hygiene changes in commit dfb27f6 — explaining why they're in this PR:

1. test/fzftab.ztst: egrep → grep -E

-         $(locale -a 2>/dev/null | egrep 'utf8|UTF-8'))
+         $(locale -a 2>/dev/null | grep -E 'utf8|UTF-8'))

egrep is obsolescent — GNU grep 3.8+ emits egrep: warning: egrep is obsolescent; using grep -E on every invocation. The %prep block runs locale -a | egrep to build the $langs array for the é = ? locale probe, so every ztst run printed the warning to stderr. grep -E is the drop-in equivalent (same POSIX ERE semantics), so the locale-detection behaviour is unchanged — it just silences the deprecation noise. This is a test-only change; no runtime code touched.

2. .gitignore: add .zcompdump

 *.zwc
+.zcompdump

The ztst harness (test/ztst.zsh → test/comptest, which sets export ZDOTDIR=$ZTST_testdir) generates a .zcompdump in the repo root on every test run. It's a generated cache file (60KB, machine-specific), not source. It got accidentally committed twice while iterating on this PR (I had to git rm --cached it both times). Adding it to .gitignore prevents it from ever being staged again. The existing *.zwc entry already ignores the compiled zsh bytecode; .zcompdump is the same class of generated artefact.

Both are unrelated to the --tmux/--popup fix itself but were necessary to keep the test suite clean and warning-free while running the new test/ftb-tmux-popup.ztst cases. Happy to split them into a separate commit if preferred.