[PATCH 6/8] lei inspect: support reading eml from --stdin

[Eric Wong <e@80x24.org>]

This can be useful inside mutt since I was diagnosing why
a label ("L:$FOO") search was giving me a false-positive
search result...
---
 lib/PublicInbox/LEI.pm        |  4 ++--
 lib/PublicInbox/LeiInspect.pm | 40 ++++++++++++++++++++++++++++++-----
 2 files changed, 37 insertions(+), 7 deletions(-)

diff --git a/lib/PublicInbox/LEI.pm b/lib/PublicInbox/LEI.pm
index 8b6c1d36..098a45ba 100644
--- a/lib/PublicInbox/LEI.pm
+++ b/lib/PublicInbox/LEI.pm
@@ -279,8 +279,8 @@ our %CMD = ( # sorted in order of importance/use:
 		'git-config(1) wrapper for '._config_path($_[0]);
 	}, qw(config-file|system|global|file|f=s), # for conflict detection
 	 qw(c=s@ C=s@), pass_through('git config') ],
-'inspect' => [ 'ITEMS...', 'inspect lei/store and/or local external',
-	qw(pretty ascii dir=s), @c_opt ],
+'inspect' => [ 'ITEMS...|--stdin', 'inspect lei/store and/or local external',
+	qw(stdin| pretty ascii dir=s), @c_opt ],
 
 'init' => [ '[DIRNAME]', sub {
 	"initialize storage, default: ".store_path($_[0]);
diff --git a/lib/PublicInbox/LeiInspect.pm b/lib/PublicInbox/LeiInspect.pm
index 2ade17af..25bd47e7 100644
--- a/lib/PublicInbox/LeiInspect.pm
+++ b/lib/PublicInbox/LeiInspect.pm
@@ -9,6 +9,7 @@ package PublicInbox::LeiInspect;
 use strict;
 use v5.10.1;
 use PublicInbox::Config;
+use PublicInbox::MID qw(mids);
 
 sub inspect_blob ($$) {
 	my ($lei, $oidhex) = @_;
@@ -184,6 +185,32 @@ sub inspect1 ($$$) {
 	1;
 }
 
+sub _inspect_argv ($$) {
+	my ($lei, $argv) = @_;
+	my $multi = scalar(@$argv) > 1;
+	$lei->out('[') if $multi;
+	while (defined(my $x = shift @$argv)) {
+		inspect1($lei, $x, scalar(@$argv)) or return;
+	}
+	$lei->out(']') if $multi;
+}
+
+sub ins_add { # InputPipe->consume callback
+	my ($lei) = @_; # $_[1] = $rbuf
+	if (defined $_[1]) {
+		$_[1] eq '' and return eval {
+			my $str = delete $lei->{istr};
+			$str =~ s/\A[\r\n]*From [^\r\n]*\r?\n//s;
+			my $eml = PublicInbox::Eml->new(\$str);
+			_inspect_argv($lei, [ 'blob:'.$lei->git_blob_id($eml),
+				map { "mid:$_" } @{mids($eml)} ]);
+		};
+		$lei->{istr} .= $_[1];
+	} else {
+		$lei->fail("error reading stdin: $!");
+	}
+}
+
 sub lei_inspect {
 	my ($lei, @argv) = @_;
 	$lei->{json} = ref(PublicInbox::Config::json())->new->utf8->canonical;
@@ -196,12 +223,15 @@ sub lei_inspect {
 	}
 	$lei->start_pager if -t $lei->{1};
 	$lei->{1}->autoflush(0);
-	my $multi = scalar(@argv) > 1;
-	$lei->out('[') if $multi;
-	while (defined(my $x = shift @argv)) {
-		inspect1($lei, $x, scalar(@argv)) or return;
+	if ($lei->{opt}->{stdin}) {
+		return $lei->fail(<<'') if @argv;
+no args allowed on command-line with --stdin
+
+		require PublicInbox::InputPipe;
+		PublicInbox::InputPipe::consume($lei->{0}, \&ins_add, $lei);
+		return;
 	}
-	$lei->out(']') if $multi;
+	_inspect_argv($lei, \@argv);
 }
 
 sub _complete_inspect {