[RFC/PATCH v6 2/2] gitweb: Smarter snapshot names

[Jakub Narebski <jnareb@gmail.com>]

From: Mark Rada <marada@uwaterloo.ca>

Teach gitweb how to produce nicer snapshot names by only using the
short hash id.  If clients make requests using a tree-ish that is not
a partial or full SHA-1 hash, then the short hash will also be appended
to whatever they asked for.  If clients request snapshot of a tag
(which means that $hash ('h') parameter has 'refs/tags/' prefix),
use only tag name.

This also includes tests cases for t9502-gitweb-standalone-parse-output.

Signed-off-by: Mark Rada <marada@uwaterloo.ca>
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
Signed-off-by: Jakub Narebski <jnareb@gmail.com>
---
This is currently an RFC because commit message does not describe
changes completely.  Among others it doesn't describe current rules.
Also tests could be better described.

Changes since v5 (by Mark Rada):
- put common parts of git_get_full_hash and git_get_short_hash 
  into git_get_hash, do not do double verification
- separate finding snapshot name and prefix in snapshot_name()
  subroutine, more smarts for snapshot name
- improved tests (use 'tar' snapshot format, testing new smarts,
  testing prefix)

 gitweb/gitweb.perl                        |   76 +++++++++++++++----
 t/t9502-gitweb-standalone-parse-output.sh |  112 +++++++++++++++++++++++++++++
 2 files changed, 172 insertions(+), 16 deletions(-)
 create mode 100755 t/t9502-gitweb-standalone-parse-output.sh

diff --git a/gitweb/gitweb.perl b/gitweb/gitweb.perl
index 8d4a2ae..d8dfd95 100755
--- a/gitweb/gitweb.perl
+++ b/gitweb/gitweb.perl
@@ -1983,16 +1983,27 @@ sub quote_command {
 
 # get HEAD ref of given project as hash
 sub git_get_head_hash {
-	my $project = shift;
+	return git_get_full_hash(shift, 'HEAD');
+}
+
+sub git_get_full_hash {
+	return git_get_hash(@_);
+}
+
+sub git_get_short_hash {
+	return git_get_hash(@_, '--short=7');
+}
+
+sub git_get_hash {
+	my ($project, $hash, @options) = @_;
 	my $o_git_dir = $git_dir;
 	my $retval = undef;
 	$git_dir = "$projectroot/$project";
-	if (open my $fd, "-|", git_cmd(), "rev-parse", "--verify", "HEAD") {
-		my $head = <$fd>;
+	if (open my $fd, '-|', git_cmd(), 'rev-parse',
+	    '--verify', '-q', @options, $hash) {
+		$retval = <$fd>;
+		chomp $retval if defined $retval;
 		close $fd;
-		if (defined $head && $head =~ /^([0-9a-fA-F]{40})$/) {
-			$retval = $1;
-		}
 	}
 	if (defined $o_git_dir) {
 		$git_dir = $o_git_dir;
@@ -5179,6 +5190,43 @@ sub git_tree {
 	git_footer_html();
 }
 
+sub snapshot_name {
+	my ($project, $hash) = @_;
+
+	# path/to/project.git  -> project
+	# path/to/project/.git -> project
+	my $name = to_utf8($project);
+	$name =~ s,([^/])/*\.git$,$1,;
+	$name = basename($name);
+	# sanitize name
+	$name =~ s/[[:cntrl:]]/?/g;
+
+	my $ver = $hash;
+	if ($hash =~ /^[0-9a-fA-F]+$/) {
+		# shorten SHA-1 hash
+		my $full_hash = git_get_full_hash($project, $hash);
+		if ($full_hash =~ /^$hash/ && length($hash) > 7) {
+			$ver = git_get_short_hash($project, $hash);
+		}
+	} elsif ($hash =~ m!^refs/tags/(.*)$!) {
+		# tags don't need shortened SHA-1 hash
+		$ver = $1;
+	} else {
+		# branches and other need shortened SHA-1 hash
+		if ($hash =~ m!^refs/(?:heads|remotes)/(.*)$!) {
+			$ver = $1;
+		}
+		$ver .= '-' . git_get_short_hash($project, $hash);
+	}
+	# in case of hierarchical branch names
+	$ver =~ s!/!.!g;
+
+	# name = project-version_string
+	$name = "$name-$ver";
+
+	return wantarray ? ($name, $name) : $name;
+}
+
 sub git_snapshot {
 	my $format = $input_params{'snapshot_format'};
 	if (!@snapshot_fmts) {
@@ -5203,24 +5251,20 @@ sub git_snapshot {
 		die_error(400, 'Object is not a tree-ish');
 	}
 
-	my $name = $project;
-	$name =~ s,([^/])/*\.git$,$1,;
-	$name = basename($name);
-	my $filename = to_utf8($name);
-	$name =~ s/\047/\047\\\047\047/g;
-	my $cmd;
-	$filename .= "-$hash$known_snapshot_formats{$format}{'suffix'}";
-	$cmd = quote_command(
+	my ($name, $prefix) = snapshot_name($project, $hash);
+	my $filename = "$name$known_snapshot_formats{$format}{'suffix'}";
+	my $cmd = quote_command(
 		git_cmd(), 'archive',
 		"--format=$known_snapshot_formats{$format}{'format'}",
-		"--prefix=$name/", $hash);
+		"--prefix=$prefix/", $hash);
 	if (exists $known_snapshot_formats{$format}{'compressor'}) {
 		$cmd .= ' | ' . quote_command(@{$known_snapshot_formats{$format}{'compressor'}});
 	}
 
+	$filename =~ s/(["\\])/\\$1/g;
 	print $cgi->header(
 		-type => $known_snapshot_formats{$format}{'type'},
-		-content_disposition => 'inline; filename="' . "$filename" . '"',
+		-content_disposition => 'inline; filename="' . $filename . '"',
 		-status => '200 OK');
 
 	open my $fd, "-|", $cmd
diff --git a/t/t9502-gitweb-standalone-parse-output.sh b/t/t9502-gitweb-standalone-parse-output.sh
new file mode 100755
index 0000000..fbf4e26
--- /dev/null
+++ b/t/t9502-gitweb-standalone-parse-output.sh
@@ -0,0 +1,112 @@
+#!/bin/sh
+#
+# Copyright (c) 2009 Mark Rada
+#
+
+test_description='gitweb as standalone script (parsing script output).
+
+This test runs gitweb (git web interface) as a CGI script from the
+commandline, and checks that it produces the correct output, either
+in the HTTP header or the actual script output.'
+
+
+. ./gitweb-lib.sh
+
+# ----------------------------------------------------------------------
+# snapshot file name
+
+cat >>gitweb_config.perl <<\EOF
+
+$known_snapshot_formats{'tar'} = {
+	'display' => 'tar',
+	'type' => 'application/x-tar',
+	'suffix' => '.tar',
+	'format' => 'tar',
+};
+
+$feature{'snapshot'}{'default'} = ['tar'];
+EOF
+
+test_expect_success setup '
+	test_commit first foo &&
+	git branch xx/test &&
+	FULL_ID=$(git rev-parse --verify HEAD) &&
+	SHORT_ID=$(git rev-parse --verify --short=7 HEAD)
+'
+test_debug '
+	echo "FULL_ID  = $FULL_ID"
+	echo "SHORT_ID = $SHORT_ID"
+'
+
+test_expect_success 'snapshots: give full hash' '
+	gitweb_run "p=.git;a=snapshot;h=$FULL_ID;sf=tar" &&
+	grep ".git-$SHORT_ID.tar" gitweb.headers
+'
+test_debug 'cat gitweb.headers'
+test_debug 'cat gitweb.log'
+
+test_expect_success 'snapshots: give short hash' '
+	gitweb_run "p=.git;a=snapshot;h=$SHORT_ID;sf=tar" &&
+	grep ".git-$SHORT_ID.tar" gitweb.headers
+'
+test_debug 'cat gitweb.headers'
+
+test_expect_success 'snapshots: give almost full hash' '
+	ID=$(git rev-parse --short=30 HEAD) &&
+	gitweb_run "p=.git;a=snapshot;h=$ID;sf=tar" &&
+	grep ".git-$SHORT_ID.tar" gitweb.headers
+'
+test_debug 'cat gitweb.headers'
+
+test_expect_success 'snapshots: give HEAD' '
+	gitweb_run "p=.git;a=snapshot;h=HEAD;sf=tar" &&
+	grep ".git-HEAD-$SHORT_ID.tar" gitweb.headers
+'
+test_debug 'cat gitweb.headers'
+
+test_expect_success 'snapshots: give short branch name' '
+	gitweb_run "p=.git;a=snapshot;h=master;sf=tar" &&
+	ID=$(git rev-parse --verify --short=7 master) &&
+	grep ".git-master-$ID.tar" gitweb.headers
+'
+test_debug 'cat gitweb.headers'
+
+test_expect_success 'snapshots: give short tag name' '
+	gitweb_run "p=.git;a=snapshot;h=first;sf=tar" &&
+	ID=$(git rev-parse --verify --short=7 first) &&
+	grep ".git-first-$ID.tar" gitweb.headers
+'
+test_debug 'cat gitweb.headers'
+
+test_expect_success 'snapshots: give full branch name' '
+	gitweb_run "p=.git;a=snapshot;h=refs/heads/master;sf=tar" &&
+	ID=$(git rev-parse --verify --short=7 master) &&
+	grep ".git-master-$ID.tar" gitweb.headers
+'
+test_debug 'cat gitweb.headers'
+
+test_expect_success 'snapshots: give full tag name' '
+	gitweb_run "p=.git;a=snapshot;h=refs/tags/first;sf=tar" &&
+	grep ".git-first.tar" gitweb.headers
+'
+test_debug 'cat gitweb.headers'
+
+test_expect_success 'snapshots: give hierarchical branch name' '
+	gitweb_run "p=.git;a=snapshot;h=xx/test;sf=tar" &&
+	grep -v "filename=.*/" gitweb.headers
+'
+test_debug 'cat gitweb.headers'
+
+cat >expected <<EOF
+.git-HEAD-$SHORT_ID/
+.git-HEAD-$SHORT_ID/foo
+EOF
+test_expect_success 'snapshots: check prefix' '
+	gitweb_run "p=.git;a=snapshot;h=HEAD;sf=tar" &&
+	grep ".git-HEAD-$SHORT_ID.tar" gitweb.headers &&
+	"$TAR" tf gitweb.body >actual &&
+	test_cmp expected actual
+'
+test_debug 'cat gitweb.headers'
+
+test_done
-- 
1.6.5