[RFC/PATCH 2/2] gitweb: check given hash before trying to create snapshot

[Mark Rada <marada@uwaterloo.ca>]

This patch is dual purposed.

First, it makes things nicer in cases when you hand craft the snapshot
URL but make a typo (e.g. netx instead of next); you will now get an
error message instead of a broken tarball.

Second, any given treeish will always be translated to the full length,
unambiguous, hash id; this will be useful for things like creating
unique names for snapshot caches.

This patch includes test for t9501 to demonstrate the changed
functionality.

Signed-off-by: Mark Rada <marada@uwaterloo.ca>
---
 gitweb/gitweb.perl                       |    5 +++--
 t/t9501-gitweb-standalone-http-status.sh |   26 ++++++++++++++++++++++++++
 2 files changed, 29 insertions(+), 2 deletions(-)

diff --git a/gitweb/gitweb.perl b/gitweb/gitweb.perl
index d650188..4ae960c 100755
--- a/gitweb/gitweb.perl
+++ b/gitweb/gitweb.perl
@@ -5197,8 +5197,9 @@ sub git_snapshot {
 		die_error(403, "Unsupported snapshot format");
 	}
 
-	if (!defined $hash) {
-		$hash = &git_get_hash($project);
+	my $snapshot = &git_get_hash($project, $hash);
+	if (!$snapshot) {
+		die_error(400, "Not a valid hash id: $hash");
 	}
 
 	my $name = $project;
diff --git a/t/t9501-gitweb-standalone-http-status.sh b/t/t9501-gitweb-standalone-http-status.sh
index d0ff21d..4f8f147 100644
--- a/t/t9501-gitweb-standalone-http-status.sh
+++ b/t/t9501-gitweb-standalone-http-status.sh
@@ -75,4 +75,30 @@ test_expect_success \
 test_debug 'cat gitweb.output'
 
 
+test_expect_success \
+	'snapshots: bad treeish id' \
+	'gitweb_run "p=.git;a=snapshot;h=frizzumFrazzum;sf=tgz" &&
+	grep "400 - Not a valid hash id:" gitweb.output'
+test_debug 'cat gitweb.output'
+
+test_expect_success \
+	'snapshots: good treeish id' \
+	'gitweb_run "p=.git;a=snapshot;h=master;sf=tgz" &&
+	grep "Status: 200 OK" gitweb.output'
+test_debug 'cat gitweb.output'
+
+test_expect_success \
+	'snapshots: good object id' \
+	'ID=`git rev-parse --verify HEAD` &&
+	gitweb_run "p=.git;a=snapshot;h=$ID;sf=tgz" &&
+	grep "Status: 200 OK" gitweb.output'
+test_debug 'cat gitweb.output'
+
+test_expect_success \
+	'snapshots: bad object id' \
+	'gitweb_run "p=.git;a=snapshot;h=abcdef01234;sf=tgz" &&
+	grep "400 - Not a valid hash id:" gitweb.output'
+test_debug 'cat gitweb.output'
+
+
 test_done
-- 
1.6.4.2