+ $x =~ s/\r?\n/\n/gs;
+ $ctx->{-anchors} = {} if $x =~ /^diff --git /sm;
+ flush_diff($ctx, \$x); # undefs $x
+ # TODO: should there be another textarea which attempts to
+ # search for the exact email which was applied to make this
+ # commit?
+ if (my $qry = delete $ctx->{-qry}) {
+ my $q = '';
+ for (@{$qry->{dfpost}}, @{$qry->{dfpre}}) {
+ # keep blobs as short as reasonable, emails
+ # are going to be older than what's in git
+ substr($_, 7, 64, '');
+ $q .= "dfblob:$_ ";
+ }
+ chop $q; # no trailing SP
+ local $Text::Wrap::columns = PublicInbox::View::COLS;
+ local $Text::Wrap::huge = 'overflow';
+ $q = wrap('', '', $q);
+ my $rows = ($q =~ tr/\n/\n/) + 1;
+ $q = ascii_html($q);
+ my $ibx_url = ibx_url_for($ctx);
+ my $alt;
+ if (defined $ibx_url) {
+ $alt = " `$ibx_url'";
+ $ibx_url =~ m!://! or
+ substr($ibx_url, 0, 0, '../../../');
+ $ibx_url = ascii_html($ibx_url);
+ } else {
+ $ibx_url = $upfx;
+ $alt = '';
+ }
+ print $zfh <<EOM;
+<hr><form action="$ibx_url"
+id=related><pre>find related emails, including ancestors/descendants/conflicts
+<textarea name=q cols=${\PublicInbox::View::COLS} rows=$rows>$q</textarea>
+<input type=submit value="search$alt"
+/>\t(<a href="${ibx_url}_/text/help/">help</a>)</pre></form>
+EOM
+ }
+ }
+ chop($x = <<EOM);
+<hr><pre>glossary
+--------
+<dfn
+id=commit>Commit</dfn> objects reference one tree, and zero or more parents.
+
+Single <dfn
+id=parent>parent</dfn> commits can typically generate a patch in
+unified diff format via `git format-patch'.
+
+Multiple <dfn id=parents>parents</dfn> means the commit is a merge.
+
+<dfn id=root_commit>Root commits</dfn> have no ancestor. Note that it is
+possible to have multiple root commits when merging independent histories.
+
+Every commit references one top-level <dfn id=tree>tree</dfn> object.</pre>
+EOM
+ delete($ctx->{-wcb})->($ctx->html_done($x));
+}
+
+sub stream_patch_parse_hdr { # {parse_hdr} for Qspawn
+ my ($r, $bref, $ctx) = @_;
+ if (!defined $r) { # sysread error
+ html_page($ctx, 500, dbg_log($ctx));
+ } elsif (index($$bref, "\n\n") >= 0) {
+ my $eml = bless { hdr => $bref }, 'PublicInbox::Eml';
+ my $fn = to_filename($eml->header('Subject') // '');
+ $fn = substr($fn // 'PATCH-no-subject', 6); # drop "PATCH-"
+ return [ 200, [ 'Content-Type', 'text/plain; charset=UTF-8',
+ 'Content-Disposition',
+ qq(inline; filename=$fn.patch) ] ];
+ } elsif ($r == 0) {
+ my $log = dbg_log($ctx);
+ warn "premature EOF on $ctx->{patch_oid} $log";
+ return html_page($ctx, 500, $log);
+ } else {
+ undef; # bref keeps growing until "\n\n"