lei: do_env combines fchdir and local

This will make switching $lei contexts less error-prone
and hopefully save us from some suprising bugs in the future.

Followup-to: 759885e60e59 (lei: ensure --stdin sets %ENV and $current_lei, 2023-09-14)

8 files changed, 112 insertions, 116 deletions

diff --git a/lib/PublicInbox/LEI.pm b/lib/PublicInbox/LEI.pm
index 8362800d..3408551b 100644
--- a/lib/PublicInbox/LEI.pm
+++ b/lib/PublicInbox/LEI.pm
@@ -479,7 +479,6 @@ sub _drop_wq {
 # pronounced "exit": x_it(1 << 8) => exit(1); x_it(13) => SIGPIPE
 sub x_it ($$) {
         my ($self, $code) = @_;
-        local $current_lei = $self;
         # make sure client sees stdout before exit
         $self->{1}->autoflush(1) if $self->{1};
         stop_pager($self);
@@ -514,7 +513,6 @@ sub qfin { # show message on finalization (LeiFinmsg)
 
 sub fail_handler ($;$$) {
         my ($lei, $code, $io) = @_;
-        local $current_lei = $lei;
         close($io) if $io; # needed to avoid warnings on SIGPIPE
         _drop_wq($lei);
         x_it($lei, $code // (1 << 8));
@@ -785,11 +783,19 @@ sub lazy_cb ($$$) { # $pfx is _complete_ or lei_
                 $pkg->can($pfx.$ucmd) : undef;
 }
 
+sub do_env {
+        my $lei = shift;
+        fchdir($lei);
+        my $cb = shift // return ($lei, %{$lei->{env}}) ;
+        local ($current_lei, %ENV) = ($lei, %{$lei->{env}});
+        $cb = $lei->can($cb) if !ref($cb); # $cb may be a scalar sub name
+        eval { $cb->($lei, @_) };
+        $lei->fail($@) if $@;
+}
+
 sub dispatch {
         my ($self, $cmd, @argv) = @_;
-        fchdir($self);
-        local %ENV = %{$self->{env}};
-        local $current_lei = $self; # for __WARN__
+        local ($current_lei, %ENV) = do_env($self);
         $self->{2}->autoflush(1); # keep stdout buffered until x_it|DESTROY
         return _help($self, 'no command given') unless defined($cmd);
         # do not support Getopt bundling for this
diff --git a/lib/PublicInbox/LeiAuth.pm b/lib/PublicInbox/LeiAuth.pm
index 9b09cecf..76a4410d 100644
--- a/lib/PublicInbox/LeiAuth.pm
+++ b/lib/PublicInbox/LeiAuth.pm
@@ -57,7 +57,7 @@ sub net_merge_all { # called in wq worker via wq_broadcast
 # called by top-level lei-daemon when first worker is done with auth
 # passes updated net auth info to current workers
 sub net_merge_continue {
-        my ($wq, $lei, $net_new) = @_;
+        my ($lei, $wq, $net_new) = @_;
         $wq->{-net_new} = $net_new; # for "lei up"
         $wq->wq_broadcast('PublicInbox::LeiAuth::net_merge_all', $net_new);
         $wq->net_merge_all_done($lei); # defined per-WQ
@@ -65,7 +65,7 @@ sub net_merge_continue {
 
 sub op_merge { # prepares PktOp->pair ops
         my ($self, $ops, $wq, $lei) = @_;
-        $ops->{net_merge_continue} = [ \&net_merge_continue, $wq, $lei ];
+        $ops->{net_merge_continue} = [ \&net_merge_continue, $lei, $wq ];
 }
 
 sub new { bless \(my $x), __PACKAGE__ }
diff --git a/lib/PublicInbox/LeiConfig.pm b/lib/PublicInbox/LeiConfig.pm
index 76fc43e7..b3495487 100644
--- a/lib/PublicInbox/LeiConfig.pm
+++ b/lib/PublicInbox/LeiConfig.pm
@@ -16,24 +16,21 @@ sub cfg_do_edit ($;$) {
         # run in script/lei foreground
         my ($op_c, $op_p) = PublicInbox::PktOp->pair;
         # $op_p will EOF when $EDITOR is done
-        $op_c->{ops} = { '' => [\&cfg_edit_done, $self] };
+        $op_c->{ops} = { '' => [\&cfg_edit_done, $lei, $self] };
         $lei->send_exec_cmd([ @$lei{qw(0 1 2)}, $op_p->{op_p} ], $cmd, $env);
 }
 
-sub cfg_edit_done { # PktOp
-        my ($self) = @_;
-        eval {
-                open my $fh, '+>', undef or die "open($!)";
-                my $cfg = do {
-                        local $self->{lei}->{2} = $fh;
-                        $self->{lei}->cfg_dump($self->{-f});
-                } or do {
-                        seek($fh, 0, SEEK_SET);
-                        return cfg_do_edit($self, do { local $/; <$fh> });
-                };
-                $self->cfg_verify($cfg) if $self->can('cfg_verify');
+sub cfg_edit_done { # PktOp lei->do_env cb
+        my ($lei, $self) = @_;
+        open my $fh, '+>', undef or die "open($!)";
+        my $cfg = do {
+                local $lei->{2} = $fh;
+                $lei->cfg_dump($self->{-f});
+        } or do {
+                seek($fh, 0, SEEK_SET);
+                return cfg_do_edit($self, do { local $/; <$fh> });
         };
-        $self->{lei}->fail($@) if $@;
+        $self->cfg_verify($cfg) if $self->can('cfg_verify');
 }
 
 sub lei_config {
diff --git a/lib/PublicInbox/LeiInspect.pm b/lib/PublicInbox/LeiInspect.pm
index 0455e739..f801610f 100644
--- a/lib/PublicInbox/LeiInspect.pm
+++ b/lib/PublicInbox/LeiInspect.pm
@@ -251,24 +251,20 @@ sub inspect_start ($$) {
         $self->wq_close;
 }
 
+sub do_inspect { # lei->do_env cb
+        my ($lei) = @_;
+        my $str = delete $lei->{istr};
+        $str =~ s/\A[\r\n]*From [^\r\n]*\r?\n//s;
+        my $eml = PublicInbox::Eml->new(\$str);
+        inspect_start($lei, [ 'blob:'.$lei->git_oid($eml)->hexdigest,
+                        map { "mid:$_" } @{mids($eml)} ]);
+}
+
 sub ins_add { # InputPipe->consume callback
         my ($lei) = @_; # $_[1] = $rbuf
-        if (defined $_[1]) {
-                $_[1] eq '' and return eval {
-                        $lei->fchdir;
-                        local %ENV = %{$lei->{env}};
-                        local $PublicInbox::LEI::current_lei = $lei;
-                        my $str = delete $lei->{istr};
-                        $str =~ s/\A[\r\n]*From [^\r\n]*\r?\n//s;
-                        my $eml = PublicInbox::Eml->new(\$str);
-                        inspect_start($lei, [
-                                'blob:'.$lei->git_oid($eml)->hexdigest,
-                                map { "mid:$_" } @{mids($eml)} ]);
-                };
-                $lei->{istr} .= $_[1];
-        } else {
-                $lei->fail("error reading stdin: $!");
-        }
+        $_[1] // return $lei->fail("error reading stdin: $!");
+        return $lei->{istr} .= $_[1] if $_[1] ne '';
+        $lei->do_env(\&do_inspect);
 }
 
 sub lei_inspect {
diff --git a/lib/PublicInbox/LeiLcat.pm b/lib/PublicInbox/LeiLcat.pm
index 7ed191c3..72875dc6 100644
--- a/lib/PublicInbox/LeiLcat.pm
+++ b/lib/PublicInbox/LeiLcat.pm
@@ -122,19 +122,18 @@ could not extract Message-ID from $x
         @q ? join(' OR ', @q) : $lei->fail("no Message-ID in: @argv");
 }
 
+sub do_lcat { # lei->do_env cb
+        my ($lei) = @_;
+        my @argv = split(/\s+/, $lei->{mset_opt}->{qstr});
+        $lei->{mset_opt}->{qstr} = extract_all($lei, @argv) or return;
+        $lei->_start_query;
+}
+
 sub _stdin { # PublicInbox::InputPipe::consume callback for --stdin
         my ($lei) = @_; # $_[1] = $rbuf
         $_[1] // return $lei->fail("error reading stdin: $!");
         return $lei->{mset_opt}->{qstr} .= $_[1] if $_[1] ne '';
-        eval {
-                $lei->fchdir;
-                local %ENV = %{$lei->{env}};
-                local $PublicInbox::LEI::current_lei = $lei;
-                my @argv = split(/\s+/, $lei->{mset_opt}->{qstr});
-                $lei->{mset_opt}->{qstr} = extract_all($lei, @argv) or return;
-                $lei->_start_query;
-        };
-        $lei->fail($@) if $@;
+        $lei->do_env(\&do_lcat);
 }
 
 sub lei_lcat {
diff --git a/lib/PublicInbox/LeiQuery.pm b/lib/PublicInbox/LeiQuery.pm
index a23354f0..e2d8a096 100644
--- a/lib/PublicInbox/LeiQuery.pm
+++ b/lib/PublicInbox/LeiQuery.pm
@@ -59,20 +59,19 @@ sub _start_query { # used by "lei q" and "lei up"
         $lxs->do_query($self);
 }
 
+sub do_qry { # do_env cb
+        my ($lei) = @_;
+        $lei->{mset_opt}->{q_raw} = $lei->{mset_opt}->{qstr};
+        $lei->{lse}->query_approxidate($lei->{lse}->git,
+                                        $lei->{mset_opt}->{qstr});
+        _start_query($lei);
+}
+
 sub qstr_add { # PublicInbox::InputPipe::consume callback for --stdin
         my ($lei) = @_; # $_[1] = $rbuf
         $_[1] // $lei->fail("error reading stdin: $!");
         return $lei->{mset_opt}->{qstr} .= $_[1] if $_[1] ne '';
-        eval {
-                $lei->fchdir;
-                local %ENV = %{$lei->{env}};
-                local $PublicInbox::LEI::current_lei = $lei;
-                $lei->{mset_opt}->{q_raw} = $lei->{mset_opt}->{qstr};
-                $lei->{lse}->query_approxidate($lei->{lse}->git,
-                                                $lei->{mset_opt}->{qstr});
-                _start_query($lei);
-        };
-        $lei->fail($@) if $@;
+        $lei->do_env(\&do_qry);
 }
 
 # make the URI||PublicInbox::{Inbox,ExtSearch} a config-file friendly string
diff --git a/lib/PublicInbox/LeiXSearch.pm b/lib/PublicInbox/LeiXSearch.pm
index 4e0849e8..8f63149e 100644
--- a/lib/PublicInbox/LeiXSearch.pm
+++ b/lib/PublicInbox/LeiXSearch.pm
@@ -405,62 +405,54 @@ sub xsearch_done_wait { # awaitpid cb
 
 sub query_done { # EOF callback for main daemon
         my ($lei) = @_;
-        local $PublicInbox::LEI::current_lei = $lei;
-        eval {
-                my $l2m = delete $lei->{l2m};
-                delete $lei->{lxs};
-                ($lei->{opt}->{'mail-sync'} && !$lei->{sto}) and
-                        warn "BUG: {sto} missing with --mail-sync";
-                $lei->sto_done_request if $lei->{sto};
-                if (my $v2w = delete $lei->{v2w}) {
-                        my $wait = $v2w->wq_do('done'); # may die
-                        $v2w->wq_close;
-                }
-                $lei->{ovv}->ovv_end($lei);
-                if ($l2m) { # close() calls LeiToMail reap_compress
-                        if (my $out = delete $lei->{old_1}) {
-                                if (my $mbout = $lei->{1}) {
-                                        close($mbout) or die <<"";
+        my $l2m = delete $lei->{l2m};
+        delete $lei->{lxs};
+        ($lei->{opt}->{'mail-sync'} && !$lei->{sto}) and
+                warn "BUG: {sto} missing with --mail-sync";
+        $lei->sto_done_request if $lei->{sto};
+        if (my $v2w = delete $lei->{v2w}) {
+                my $wait = $v2w->wq_do('done'); # may die
+                $v2w->wq_close;
+        }
+        $lei->{ovv}->ovv_end($lei);
+        if ($l2m) { # close() calls LeiToMail reap_compress
+                if (my $out = delete $lei->{old_1}) {
+                        if (my $mbout = $lei->{1}) {
+                                close($mbout) or die <<"";
 Error closing $lei->{ovv}->{dst}: \$!=$! \$?=$?
 
-                                }
-                                $lei->{1} = $out;
-                        }
-                        if ($l2m->lock_free) {
-                                $l2m->poke_dst;
-                                $lei->poke_mua;
-                        } else { # mbox users
-                                delete $l2m->{mbl}; # drop dotlock
                         }
+                        $lei->{1} = $out;
                 }
-                if ($lei->{-progress}) {
-                        my $tot = $lei->{-mset_total} // 0;
-                        my $nr_w = $lei->{-nr_write} // 0;
-                        my $d = ($lei->{-nr_seen} // 0) - $nr_w;
-                        my $x = "$tot matches";
-                        $x .= ", $d duplicates" if $d;
-                        if ($l2m) {
-                                my $m = "# $nr_w written to " .
-                                        "$lei->{ovv}->{dst} ($x)";
-                                $nr_w ? $lei->qfin($m) : $lei->qerr($m);
-                        } else {
-                                $lei->qerr("# $x");
-                        }
+                if ($l2m->lock_free) {
+                        $l2m->poke_dst;
+                        $lei->poke_mua;
+                } else { # mbox users
+                        delete $l2m->{mbl}; # drop dotlock
                 }
-                $lei->start_mua if $l2m && !$l2m->lock_free;
-                $lei->dclose;
-        };
-        $lei->fail($@) if $@;
+        }
+        if ($lei->{-progress}) {
+                my $tot = $lei->{-mset_total} // 0;
+                my $nr_w = $lei->{-nr_write} // 0;
+                my $d = ($lei->{-nr_seen} // 0) - $nr_w;
+                my $x = "$tot matches";
+                $x .= ", $d duplicates" if $d;
+                if ($l2m) {
+                        my $m = "# $nr_w written to " .
+                                "$lei->{ovv}->{dst} ($x)";
+                        $nr_w ? $lei->qfin($m) : $lei->qerr($m);
+                } else {
+                        $lei->qerr("# $x");
+                }
+        }
+        $lei->start_mua if $l2m && !$l2m->lock_free;
+        $lei->dclose;
 }
 
 sub do_post_augment {
         my ($lei) = @_;
-        local $PublicInbox::LEI::current_lei = $lei;
         my $l2m = $lei->{l2m} or return; # client disconnected
-        eval {
-                $lei->fchdir;
-                $l2m->post_augment($lei);
-        };
+        eval { $l2m->post_augment($lei) };
         my $err = $@;
         if ($err) {
                 if (my $lxs = delete $lei->{lxs}) {
@@ -518,7 +510,7 @@ sub start_query ($$) { # always runs in main (lei-daemon) process
 }
 
 sub incr_start_query { # called whenever an l2m shard starts do_post_auth
-        my ($self, $lei) = @_;
+        my ($lei, $self) = @_;
         my $l2m = $lei->{l2m};
         return if ++$self->{nr_start_query} != $l2m->{-wq_nr_workers};
         start_query($self, $lei);
@@ -534,16 +526,16 @@ sub do_query {
         my ($self, $lei) = @_;
         my $l2m = $lei->{l2m};
         my $ops = {
-                'sigpipe_handler' => [ $lei ],
-                'fail_handler' => [ $lei ],
-                'do_post_augment' => [ \&do_post_augment, $lei ],
-                'incr_post_augment' => [ \&incr_post_augment, $lei ],
+                sigpipe_handler => [ $lei ],
+                fail_handler => [ $lei ],
+                do_post_augment => [ \&do_post_augment, $lei ],
+                incr_post_augment => [ \&incr_post_augment, $lei ],
                 '' => [ \&query_done, $lei ],
-                'mset_progress' => [ \&mset_progress, $lei ],
-                'l2m_progress' => [ \&l2m_progress, $lei ],
-                'x_it' => [ $lei ],
-                'child_error' => [ $lei ],
-                'incr_start_query' => [ $self, $lei ],
+                mset_progress => [ \&mset_progress, $lei ],
+                l2m_progress => [ \&l2m_progress, $lei ],
+                x_it => [ $lei ],
+                child_error => [ $lei ],
+                incr_start_query => [ \&incr_start_query, $lei, $self ],
         };
         $lei->{auth}->op_merge($ops, $l2m, $lei) if $l2m && $lei->{auth};
         my $end = $lei->pkt_op_pair;
diff --git a/lib/PublicInbox/PktOp.pm b/lib/PublicInbox/PktOp.pm
index dc432307..1bcdd799 100644
--- a/lib/PublicInbox/PktOp.pm
+++ b/lib/PublicInbox/PktOp.pm
@@ -1,4 +1,4 @@
-# Copyright (C) 2021 all contributors <meta@public-inbox.org>
+# Copyright (C) all contributors <meta@public-inbox.org>
 # License: AGPL-3.0+ <https://www.gnu.org/licenses/agpl-3.0.txt>
 
 # op dispatch socket, reads a message, runs a sub
@@ -6,8 +6,7 @@
 # Used for lei_xsearch and maybe other things
 # "command" => [ $sub, @fixed_operands ]
 package PublicInbox::PktOp;
-use strict;
-use v5.10.1;
+use v5.12;
 use parent qw(PublicInbox::DS);
 use Errno qw(EAGAIN ECONNRESET);
 use PublicInbox::Syscall qw(EPOLLIN);
@@ -55,7 +54,15 @@ sub event_step {
         my $op = $self->{ops}->{$cmd //= $msg};
         if ($op) {
                 my ($obj, @args) = (@$op, @pargs);
-                blessed($obj) ? $obj->$cmd(@args) : $obj->(@args);
+                if (blessed($args[0]) && $args[0]->can('do_env')) {
+                        my $lei = shift @args;
+                        $lei->do_env($obj, @args);
+                } elsif (blessed($obj)) {
+                        $obj->can('do_env') ? $obj->do_env($cmd, @args)
+                                                : $obj->$cmd(@args);
+                } else {
+                        $obj->(@args);
+                }
         } elsif ($msg ne '') {
                 die "BUG: unknown message: `$cmd'";
         }