[PATCH 2/8] viewdiff: linkify diffstats for non-format-patch emails

[Eric Wong]

Some folks unfortunately use "git diff --stat -p" to generate
patches.  These messages lack the /^---$/ line and causing
diffstats to not get linkified properly.  We now treat the
/^---$/ as optional and rely on the presence of file lines with
/ \| / proceeding a /\d+ files? changed,/ line.
---
 lib/PublicInbox/ViewDiff.pm | 41 +++++++++++++++++--------------------
 lib/PublicInbox/ViewVCS.pm  |  2 +-
 2 files changed, 20 insertions(+), 23 deletions(-)

diff --git a/lib/PublicInbox/ViewDiff.pm b/lib/PublicInbox/ViewDiff.pm
index 960f7e61..ee2d688c 100644
--- a/lib/PublicInbox/ViewDiff.pm
+++ b/lib/PublicInbox/ViewDiff.pm
@@ -166,29 +166,26 @@ sub diff_before_or_after ($$) {
        my ($ctx, $x) = @_;
        my $linkify = $ctx->{-linkify};
        my $dst = $ctx->{obuf};
-       my $anchors = exists($ctx->{-anchors}) ? 1 : 0;
-       for my $y (split(/(^---\n)/sm, $$x)) {
-               if ($y =~ /\A---\n\z/s) {
-                       $$dst .= "---\n"; # all HTML is "\r\n" => "\n"
-                       $anchors |= 2;
-               } elsif ($anchors == 3 && $y =~ /^ [0-9]+ files? changed, /sm) {
-                       # ok, looks like a diffstat, go line-by-line:
-                       for my $l (split(/^/m, $y)) {
-                               if ($l =~ /^ (.+)( +\| .*\z)/s) {
-                                       anchor0($dst, $ctx, $1, $2) or
-                                               $$dst .= $linkify->to_html($l);
-                               } elsif ($l =~ s/^( [0-9]+ files? )changed,//) {
-                                       $$dst .= $1;
-                                       my $end = $ctx->{end_id} // 'related';
-                                       $$dst .= "<a href=#$end>changed</a>,";
-                                       $$dst .= ascii_html($l);
-                               } else {
-                                       $$dst .= $linkify->to_html($l);
-                               }
-                       }
-               } else { # commit message, notes, etc
-                       $$dst .= $linkify->to_html($y);
+       if (exists $ctx->{-anchors} && $$x =~ /\A(.*?) # likely "---\n"
+                       # diffstat lines:
+                       ((?:^\x20(?:[^\n]+?)(?:\x20+\|\x20[^\n]*\n))+)
+                       (\x20[0-9]+\x20files?\x20)changed,([^\n]+\n)
+                       (.*?)\z/msx) { # notes, commit message, etc
+               undef $$x;
+               my @x = ($5, $4, $3, $2, $1);
+               $$dst .= $linkify->to_html(pop @x); # uninteresting prefix
+               for my $l (split(/^/m, pop(@x))) { # per-file diffstat lines
+                       $l =~ /^ (.+)( +\| .*\z)/s and
+                               anchor0($dst, $ctx, $1, $2) and next;
+                       $$dst .= $linkify->to_html($l);
                }
+               $$dst .= $x[2]; # $3 /^ \d+ files? /
+               my $end = $ctx->{end_id} // 'related';
+               $$dst .= "<a href=#$end>changed</a>,";
+               $$dst .= ascii_html($x[1]); # $4: insertions/deletions
+               $$dst .= $linkify->to_html($x[0]); # notes, commit message, etc
+       } else {
+               $$dst .= $linkify->to_html($$x);
        }
 }
 
diff --git a/lib/PublicInbox/ViewVCS.pm b/lib/PublicInbox/ViewVCS.pm
index dcb5c67f..4165a1de 100644
--- a/lib/PublicInbox/ViewVCS.pm
+++ b/lib/PublicInbox/ViewVCS.pm
@@ -153,10 +153,10 @@ EOM
                $buf = '';
                $ctx->{obuf} = \$buf;
                $ctx->{-apfx} = $ctx->{-spfx} = $upfx;
-               $ctx->{-anchors} = {};
                $bdy = '';
                read($fh, $bdy, -s _);
                $bdy =~ s/\r?\n/\n/gs;
+               $ctx->{-anchors} = {} if $bdy =~ /^diff --git /sm;
                flush_diff($ctx, \$bdy);
                $ctx->zmore($buf);
                undef $buf;