cgi: implement get_mid_txt

This is essential when telling people to use something like:
	curl $URL | git am

1 files changed, 22 insertions, 5 deletions

diff --git a/public-inbox-cgi b/public-inbox-cgi
index 912bb191..91314f06 100755
--- a/public-inbox-cgi
+++ b/public-inbox-cgi
@@ -15,6 +15,7 @@ use warnings;
 use CGI qw(:cgi :escapeHTML -nosticky); # PSGI/FastCGI/mod_perl compat
 use Encode qw(decode_utf8);
 use PublicInbox::Config;
+use Digest::SHA qw(sha1_hex);
 our $LISTNAME_RE = qr!\A/([\w\.\-]+)!;
 our $pi_config;
 BEGIN {
@@ -63,11 +64,11 @@ sub main {
                 invalid_list(\%ctx, $1) || get_atom(\%ctx, $cgi, 0);
 
         # single-message pages
-        } elsif ($path_info =~ m!$LISTNAME_RE/mid/(\S+)\.txt\z!o) {
-                get_mid_txt($cgi, $1, $2);
-        } elsif ($path_info =~ m!$LISTNAME_RE/mid/(\S+)\.html\z!o) {
-                get_mid_html($cgi, $1, $2);
-        } elsif ($path_info =~ m!$LISTNAME_RE/mid/(\S+)\z!o) {
+        } elsif ($path_info =~ m!$LISTNAME_RE/m/(\S+)\.txt\z!o) {
+                invalid_list_mid(\%ctx, $1, $2) || get_mid_txt(\%ctx, $cgi);
+        } elsif ($path_info =~ m!$LISTNAME_RE/m/(\S+)\.html\z!o) {
+                invalid_list_mid(\%ctx, $1, $2) || get_mid_html(\%ctx, $cgi);
+        } elsif ($path_info =~ m!$LISTNAME_RE/m/(\S+)\z!o) {
                 redirect_mid_html($cgi, $1, $2);
         } else {
                 r404();
@@ -126,3 +127,19 @@ sub get_index {
                 })
         ];
 }
+
+sub mid2blob {
+        my ($ctx) = @_;
+        local $ENV{GIT_DIR} = $ctx->{git_dir};
+        my $hex = sha1_hex($ctx->{mid});
+        $hex =~ /\A([a-f0-9]{2})([a-f0-9]{38})\z/i or
+                        die "BUG: not a SHA-1 hex: $hex";
+        my $blob = `git cat-file blob HEAD:$1/$2 2>/dev/null`;
+        $? == 0 ? \$blob : undef;
+}
+
+sub get_mid_txt {
+        my ($ctx, $cgi) = @_;
+        my $x = mid2blob($ctx);
+        $x ? [ "200 OK", {'Content-Type' => 'text/plain'}, $$x ] : r404();
+}