[PATCH 19/22] viewdiff: add "b=" param with non-standard diff prefix

[Eric Wong <e@yhbt.net>]

<20180228012207.GB251290@aiede.svl.corp.google.com> (posted to
git@vger) uses "i" and "w" prefixes instead of the standard "a"
and "b" prefixes, ensure we emit a "b=$FILENAME" param for the
solver endpoint to improve search accuracy, syntax highlighting,
and information density in the URL itself.
---
 lib/PublicInbox/ViewDiff.pm | 9 ++++-----
 xt/solver.t                 | 2 +-
 2 files changed, 5 insertions(+), 6 deletions(-)

diff --git a/lib/PublicInbox/ViewDiff.pm b/lib/PublicInbox/ViewDiff.pm
index be0c0452..6a60d0dc 100644
--- a/lib/PublicInbox/ViewDiff.pm
+++ b/lib/PublicInbox/ViewDiff.pm
@@ -38,8 +38,7 @@ sub UNSAFE () { "^A-Za-z0-9\-\._~/" }
 
 my $OID_NULL = '0{7,40}';
 my $OID_BLOB = '[a-f0-9]{7,40}';
-my $PATH_A = '"?a/.+|/dev/null';
-my $PATH_B = '"?b/.+|/dev/null';
+my $PATH_X = '"?[^/]+/.+|/dev/null';
 
 # cf. git diff.c :: get_compact_summary
 my $DIFFSTAT_COMMENT = qr/\((?:new|gone|(?:(?:new|mode) [\+\-][lx]))\)/;
@@ -158,7 +157,7 @@ sub flush_diff ($$$) {
 			$state == DSTATE_INIT or
 				to_state($dst, $state, DSTATE_INIT);
 			$$dst .= $s;
-		} elsif ($s =~ m!^diff --git ($PATH_A) ($PATH_B)$!o) {
+		} elsif ($s =~ m!^diff --git ($PATH_X) ($PATH_X)$!o) {
 			my ($pa, $pb) = ($1, $2);
 			if ($state != DSTATE_HEAD) {
 				to_state($dst, $state, DSTATE_HEAD);
@@ -193,8 +192,8 @@ sub flush_diff ($$$) {
 			$$dst .= '</span>';
 			$state = DSTATE_CTX;
 			$$dst .= $linkify->to_html($s);
-		} elsif ($s =~ m!^--- (?:$PATH_A)!o ||
-		         $s =~ m!^\+{3} (?:$PATH_B)!o)  {
+		} elsif ($s =~ m!^--- (?:$PATH_X)!o ||
+		         $s =~ m!^\+{3} (?:$PATH_X)!o)  {
 			# color only (no oid link) if missing dctx->{oid_*}
 			$state <= DSTATE_STAT and
 				to_state($dst, $state, DSTATE_HEAD);
diff --git a/xt/solver.t b/xt/solver.t
index 5307e120..d2206b28 100644
--- a/xt/solver.t
+++ b/xt/solver.t
@@ -27,7 +27,7 @@ my $todo = {
 		'776fa90f7f/s/?b=contrib/git-jump/git-jump',
 		'5cd8845/s/?b=submodule.c',
 		'81c1164ae5/s/?b=builtin/log.c',
-		'6aa8857a11/s/?b=protocol.c', # TODO: i/, w/ instead of a/ b/
+		'6aa8857a11/s/?b=protocol.c',
 		'96f1c7f/s/', # TODO: b=contrib/completion/git-completion.bash
 		'b76f2c0/s/?b=po/zh_CN.po',
 	],