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[PATCH 3/3] gitweb: make gitweb_check_feature a boolean wrapper

From
Junio C Hamano <gitster@pobox.com>
Date
Nov 29, 2008, 21:16 UTC
Message-ID
<7vmyfiz0zf.fsf_-_@gitster.siamese.dyndns.org>
In-Reply-To
<7vzljiz1qn.fsf@gitster.siamese.dyndns.org>

The gitweb_get_feature() function retrieves the configuration parameters for the feature (such as the list of snapshot formats or the list of additional actions), but it is very often used to see if feature is enabled (which is returned as the first element in the list).

Because accepting the returned list in a scalar context by mistake yields the number of elements in the array, which is non-zero in all cases, such a mistake would result in a bug for the latter use, with disabled features appearing enabled. All existing callers that call the function for this purpose assign the return value in the list context to retrieve the first element, but that is only because we fixed careless callers recently.

This add gitweb_check_feature() as a wrapper to gitweb_get_feature() that can be called safely in the scalar context to see if a feature is enabled to reduce the risk of future bugs.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 * Again, this is to demonstrate how I would have liked to see your
   patches as a reviewable series.  Notice how this naturally justifies
   the dropping of parentheses in many lines that begin with "my", and
   makes it easier to review?  You can review the patch easily by knowing
   that callers that have s/get/check/ are now safe to use scalar context.
 gitweb/gitweb.perl |   56 +++++++++++++++++++++++++++++++++------------------
 1 files changed, 36 insertions(+), 20 deletions(-)
diff --git a/gitweb/gitweb.perl b/gitweb/gitweb.perl
index 7ab16cd..acc4cfd 100755
--- a/gitweb/gitweb.perl
+++ b/gitweb/gitweb.perl
@@ -190,7 +190,7 @@ our %feature = (
 	# if there is no 'sub' key (no feature-sub), then feature cannot be
 	# overriden
 	#
-	# use gitweb_get_feature(<feature>) to check if <feature> is enabled
+	# use gitweb_check_feature(<feature>) to check if <feature> is enabled
 
 	# Enable the 'blame' blob view, showing the last commit that modified
 	# each line in the file. This can be very CPU-intensive.
@@ -344,6 +344,22 @@ sub gitweb_get_feature {
 	return $sub->(@defaults);
 }
 
+# A wrapper to check if a given feature is enabled.
+# With this, you can say
+#
+#   my $bool_feat = gitweb_check_feature('bool_feat');
+#   gitweb_check_feature('bool_feat') or somecode;
+#
+# instead of
+#
+#   my ($bool_feat) = gitweb_get_feature('bool_feat');
+#   (gitweb_get_feature('bool_feat'))[0] or somecode;
+#
+sub gitweb_check_feature {
+	return (gitweb_get_feature(@_))[0];
+}
+
+
 sub feature_blame {
 	my ($val) = git_get_project_config('blame', '--bool');
 
@@ -810,7 +826,7 @@ sub href (%) {
 		}
 	}
 
-	my ($use_pathinfo) = gitweb_get_feature('pathinfo');
+	my $use_pathinfo = gitweb_check_feature('pathinfo');
 	if ($use_pathinfo) {
 		# try to put as many parameters as possible in PATH_INFO:
 		#   - project name
@@ -2101,7 +2117,7 @@ sub git_get_projects_list {
 	$filter ||= '';
 	$filter =~ s/\.git$//;
 
-	my ($check_forks) = gitweb_get_feature('forks');
+	my $check_forks = gitweb_check_feature('forks');
 
 	if (-d $projects_list) {
 		# search in directory
@@ -2947,7 +2963,7 @@ EOF
 	}
 	print "</div>\n";
 
-	my ($have_search) = gitweb_get_feature('search');
+	my $have_search = gitweb_check_feature('search');
 	if (defined $project && $have_search) {
 		if (!defined $searchtext) {
 			$searchtext = "";
@@ -2961,7 +2977,7 @@ EOF
 			$search_hash = "HEAD";
 		}
 		my $action = $my_uri;
-		my ($use_pathinfo) = gitweb_get_feature('pathinfo');
+		my $use_pathinfo = gitweb_check_feature('pathinfo');
 		if ($use_pathinfo) {
 			$action .= "/".esc_url($project);
 		}
@@ -3454,7 +3470,7 @@ sub is_patch_split {
 sub git_difftree_body {
 	my ($difftree, $hash, @parents) = @_;
 	my ($parent) = $parents[0];
-	my ($have_blame) = gitweb_get_feature('blame');
+	my $have_blame = gitweb_check_feature('blame');
 	print "<div class=\"list_head\">\n";
 	if ($#{$difftree} > 10) {
 		print(($#{$difftree} + 1) . " files changed:\n");
@@ -3914,7 +3930,7 @@ sub fill_project_list_info {
 	my ($projlist, $check_forks) = @_;
 	my @projects;
 
-	my ($show_ctags) = gitweb_get_feature('ctags');
+	my $show_ctags = gitweb_check_feature('ctags');
  PROJECT:
 	foreach my $pr (@$projlist) {
 		my (@activity) = git_get_last_activity($pr->{'path'});
@@ -3968,7 +3984,7 @@ sub git_project_list_body {
 	# actually uses global variable $project
 	my ($projlist, $order, $from, $to, $extra, $no_header) = @_;
 
-	my ($check_forks) = gitweb_get_feature('forks');
+	my $check_forks = gitweb_check_feature('forks');
 	my @projects = fill_project_list_info($projlist, $check_forks);
 
 	$order ||= $default_projects_order;
@@ -3988,7 +4004,7 @@ sub git_project_list_body {
 		@projects = sort {$a->{$oi->{'key'}} <=> $b->{$oi->{'key'}}} @projects;
 	}
 
-	my ($show_ctags) = gitweb_get_feature('ctags');
+	my $show_ctags = gitweb_check_feature('ctags');
 	if ($show_ctags) {
 		my %ctags;
 		foreach my $p (@projects) {
@@ -4428,7 +4444,7 @@ sub git_summary {
 	my @taglist  = git_get_tags_list(16);
 	my @headlist = git_get_heads_list(16);
 	my @forklist;
-	my ($check_forks) = gitweb_get_feature('forks');
+	my $check_forks = gitweb_check_feature('forks');
 
 	if ($check_forks) {
 		@forklist = git_get_projects_list($project);
@@ -4457,7 +4473,7 @@ sub git_summary {
 	}
 
 	# Tag cloud
-	my ($show_ctags) = gitweb_get_feature('ctags');
+	my $show_ctags = gitweb_check_feature('ctags');
 	if ($show_ctags) {
 		my $ctags = git_get_project_ctags($project);
 		my $cloud = git_populate_project_tagcloud($ctags);
@@ -4559,7 +4575,7 @@ sub git_blame {
 	my $fd;
 	my $ftype;
 
-	gitweb_get_feature('blame')[0]
+	gitweb_check_feature('blame')
 	    or die_error(403, "Blame view not allowed");
 
 	die_error(400, "No file name given") unless $file_name;
@@ -4747,7 +4763,7 @@ sub git_blob {
 		$expires = "+1d";
 	}
 
-	my ($have_blame) = gitweb_get_feature('blame');
+	my $have_blame = gitweb_check_feature('blame');
 	open my $fd, "-|", git_cmd(), "cat-file", "blob", $hash
 		or die_error(500, "Couldn't cat $file_name, $hash");
 	my $mimetype = blob_mimetype($fd, $file_name);
@@ -4840,7 +4856,7 @@ sub git_tree {
 	my $ref = format_ref_marker($refs, $hash_base);
 	git_header_html();
 	my $basedir = '';
-	my ($have_blame) = gitweb_get_feature('blame');
+	my $have_blame = gitweb_check_feature('blame');
 	if (defined $hash_base && (my %co = parse_commit($hash_base))) {
 		my @views_nav = ();
 		if (defined $file_name) {
@@ -5610,7 +5626,7 @@ sub git_history {
 }
 
 sub git_search {
-	gitweb_get_feature('search')[0] or die_error(403, "Search is disabled");
+	gitweb_check_feature('search') or die_error(403, "Search is disabled");
 	if (!defined $searchtext) {
 		die_error(400, "Text field is empty");
 	}
@@ -5629,11 +5645,11 @@ sub git_search {
 	if ($searchtype eq 'pickaxe') {
 		# pickaxe may take all resources of your box and run for several minutes
 		# with every query - so decide by yourself how public you make this feature
-		gitweb_get_feature('pickaxe')[0]
+		gitweb_check_feature('pickaxe')
 		    or die_error(403, "Pickaxe is disabled");
 	}
 	if ($searchtype eq 'grep') {
-		gitweb_get_feature('grep')[0]
+		gitweb_check_feature('grep')
 		    or die_error(403, "Grep is disabled");
 	}
 
@@ -5838,7 +5854,7 @@ insensitive).</p>
 <dt><b>commit</b></dt>
 <dd>The commit messages and authorship information will be scanned for the given pattern.</dd>
 EOT
-	my ($have_grep) = gitweb_get_feature('grep');
+	my $have_grep = gitweb_check_feature('grep');
 	if ($have_grep) {
 		print <<EOT;
 <dt><b>grep</b></dt>
@@ -5855,7 +5871,7 @@ EOT
 <dt><b>committer</b></dt>
 <dd>Name and e-mail of the committer and date of commit will be scanned for the given pattern.</dd>
 EOT
-	my ($have_pickaxe) = gitweb_get_feature('pickaxe');
+	my $have_pickaxe = gitweb_check_feature('pickaxe');
 	if ($have_pickaxe) {
 		print <<EOT;
 <dt><b>pickaxe</b></dt>
@@ -5907,7 +5923,7 @@ sub git_shortlog {
 
 sub git_feed {
 	my $format = shift || 'atom';
-	my ($have_blame) = gitweb_get_feature('blame');
+	my $have_blame = gitweb_check_feature('blame');
 
 	# Atom: http://www.atomenabled.org/developers/syndication/
 	# RSS:  http://www.notestips.com/80256B3A007F2692/1/NAMO5P9UPQ
-- 
1.6.0.4.850.g6bd829
Previous: Junio C HamanoNext: Giuseppe Bilotta
Message 10 of 26 in “[PATCHv2 0/2] fixes to gitweb feature check code”
  1. Giuseppe BilottaNov 28, 2008
  2. 1/2 gitweb: fixes to gitweb feature check codeGiuseppe Bilotta, Nov 28, 2008
  3. 2/2 gitweb: clean up git_check_feature() callsGiuseppe Bilotta, Nov 28, 2008
  4. 2/2 gitweb: clean up gitweb_check_feature() callsGiuseppe Bilotta, Nov 29, 2008
  5. Jakub NarebskiNov 29, 2008
  6. 2/2 gitweb: clean up gitweb_check_feature() callsGiuseppe Bilotta, Nov 29, 2008
  7. Junio C HamanoNov 29, 2008
  8. Junio C HamanoNov 29, 2008
  9. 2/3 gitweb: rename gitweb_check_feature to gitweb_get_featureJunio C Hamano, Nov 29, 2008
  10. 3/3 gitweb: make gitweb_check_feature a boolean wrapperJunio C Hamano, Nov 29, 2008
  11. Giuseppe BilottaNov 29, 2008
  12. Junio C HamanoNov 30, 2008
  13. Giuseppe BilottaNov 30, 2008
  14. gitweb: fixes to gitweb feature check codeGiuseppe Bilotta, Nov 30, 2008
  15. Jakub NarebskiDec 2, 2008
  16. [PATCHv3bis] gitweb: fixes to gitweb feature check codeGiuseppe Bilotta, Dec 2, 2008
  17. Junio C HamanoDec 3, 2008
  18. Junio C HamanoDec 2, 2008
  19. Jakub NarebskiDec 3, 2008
  20. Giuseppe BilottaNov 29, 2008
  21. Junio C HamanoNov 29, 2008
  22. Jakub NarebskiNov 29, 2008
  23. Jakub NarebskiNov 29, 2008
  24. Jakub NarebskiNov 30, 2008
  25. Jakub NarebskiNov 29, 2008
  26. Giuseppe BilottaNov 29, 2008

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