git-rev-list: Add regexp tuning options

index c3c2043..0dba73f 100644
@@ -25,6 +25,7 @@ SYNOPSIS
 	     [ \--cherry-pick ]
 	     [ \--encoding[=<encoding>] ]
 	     [ \--(author|committer|grep)=<pattern> ]
+	     [ \--regexp-ignore-case ] [ \--extended-regexp ]
 	     [ \--date={local|relative|default} ]
 	     [ [\--objects | \--objects-edge] [ \--unpacked ] ]
 	     [ \--pretty | \--header ]

@@ -214,6 +215,15 @@ limiting may be applied.
 	Limit the commits output to ones with log message that
 	matches the specified pattern (regular expression).
 
+--regexp-ignore-case::
+
+	Match the regexp limiting patterns without regard to letters case.
+
+--extended-regexp::
+
+	Consider the limiting patterns to be extended regular expressions
+	instead of the default basic regular expressions.
+
 --remove-empty::
 
 	Stop when a given path disappears from the tree.

index 0143183..4ccb4e3 100755
@@ -404,9 +404,6 @@ if (defined $searchtype) {
 our $searchtext = $cgi->param('s');
 our $search_regexp;
 if (defined $searchtext) {
-	if ($searchtype ne 'grep' and $searchtype ne 'pickaxe' and $searchtext =~ m/[^a-zA-Z0-9_\.\/\-\+\:\@ ]/) {
-		die_error(undef, "Invalid search parameter");
-	}
 	if (length($searchtext) < 2) {
 		die_error(undef, "At least two characters are required for search parameter");
 	}

index 4ccb4e3..846392e 100755
@@ -401,13 +401,15 @@ if (defined $searchtype) {
 	}
 }
 
+our $search_use_regexp = $cgi->param('sr');
+
 our $searchtext = $cgi->param('s');
 our $search_regexp;
 if (defined $searchtext) {
 	if (length($searchtext) < 2) {
 		die_error(undef, "At least two characters are required for search parameter");
 	}
-	$search_regexp = quotemeta $searchtext;
+	$search_regexp = $search_use_regexp ? $searchtext : quotemeta $searchtext;
 }
 
 # now read PATH_INFO and use it as alternative to parameters

@@ -535,6 +537,7 @@ sub href(%) {
 		order => "o",
 		searchtext => "s",
 		searchtype => "st",
+		search_use_regexp => "sr",
 	);
 	my %mapping = @mapping;
 

@@ -1579,7 +1582,7 @@ sub parse_commit {
 }
 
 sub parse_commits {
-	my ($commit_id, $maxcount, $skip, $arg, $filename) = @_;
+	my ($commit_id, $maxcount, $skip, $filename, @args) = @_;
 	my @cos;
 
 	$maxcount ||= 1;

@@ -1589,7 +1592,7 @@ sub parse_commits {
 
 	open my $fd, "-|", git_cmd(), "rev-list",
 		"--header",
-		($arg ? ($arg) : ()),
+		@args,
 		("--max-count=" . $maxcount),
 		("--skip=" . $skip),
 		$commit_id,

@@ -2007,6 +2010,9 @@ EOF
 		      $cgi->sup($cgi->a({-href => href(action=>"search_help")}, "?")) .
 		      " search:\n",
 		      $cgi->textfield(-name => "s", -value => $searchtext) . "\n" .
+		      "<span title=\"Extended regular expression\">" .
+		      $cgi->checkbox(-name => 'sr', -value => 1, -checked => $search_use_regexp, -label => 're') .
+		      "</span>" .
 		      "</div>" .
 		      $cgi->end_form() . "\n";
 	}

@@ -4655,7 +4661,7 @@ sub git_history {
 		$ftype = git_get_type($hash);
 	}
 
-	my @commitlist = parse_commits($hash_base, 101, (100 * $page), "--full-history", $file_name);
+	my @commitlist = parse_commits($hash_base, 101, (100 * $page), $file_name, "--full-history");
 
 	my $paging_nav = '';
 	if ($page > 0) {

@@ -4745,7 +4751,9 @@ sub git_search {
 			$greptype = "--committer=";
 		}
 		$greptype .= $search_regexp;
-		my @commitlist = parse_commits($hash, 101, (100 * $page), $greptype);
+		my @commitlist = parse_commits($hash, 101, (100 * $page), undef,
+		                               $greptype, $search_use_regexp ? ('--extended-regexp') : (),
+					       '--regexp-ignore-case');
 
 		my $paging_nav = '';
 		if ($page > 0) {

@@ -4795,8 +4803,9 @@ sub git_search {
 		my $git_command = git_cmd_str();
 		my $searchqtext = $searchtext;
 		$searchqtext =~ s/'/'\\''/;
+		my $pickaxe_flags = $search_use_regexp ? '--pickaxe-regex' : '';
 		open my $fd, "-|", "$git_command rev-list $hash | " .
-			"$git_command diff-tree -r --stdin -S\'$searchqtext\'";
+			"$git_command diff-tree -r --stdin -S\'$searchqtext\' $pickaxe_flags";
 		undef %co;
 		my @files;
 		while (my $line = <$fd>) {

@@ -4859,7 +4868,9 @@ sub git_search {
 		my $alternate = 1;
 		my $matches = 0;
 		$/ = "\n";
-		open my $fd, "-|", git_cmd(), 'grep', '-n', '-i', '-E', $searchtext, $co{'tree'};
+		open my $fd, "-|", git_cmd(), 'grep', '-n',
+			$search_use_regexp ? ('-E', '-i') : '-F',
+			$searchtext, $co{'tree'};
 		my $lastfile = '';
 		while (my $line = <$fd>) {
 			chomp $line;

@@ -4889,7 +4900,7 @@ sub git_search {
 				print "<div class=\"binary\">Binary file</div>\n";
 			} else {
 				$ltext = untabify($ltext);
-				if ($ltext =~ m/^(.*)($searchtext)(.*)$/i) {
+				if ($ltext =~ m/^(.*)($search_regexp)(.*)$/i) {
 					$ltext = esc_html($1, -nbsp=>1);
 					$ltext .= '<span class="match">';
 					$ltext .= esc_html($2, -nbsp=>1);

@@ -4924,27 +4935,31 @@ sub git_search_help {
 	git_header_html();
 	git_print_page_nav('','', $hash,$hash,$hash);
 	print <<EOT;
+<p><strong>Pattern</strong> is by default a normal string that is matched precisely (but without
+regard to case, except in the case of pickaxe). However, when you check the <em>re</em> checkbox,
+the pattern entered is recognized as the POSIX extended
+<a href="http://en.wikipedia.org/wiki/Regular_expression">regular expression</a> (also case
+insensitive).</p>
 <dl>
 <dt><b>commit</b></dt>
-<dd>The commit messages and authorship information will be scanned for the given string.</dd>
+<dd>The commit messages and authorship information will be scanned for the given pattern.</dd>
 EOT
 	my ($have_grep) = gitweb_check_feature('grep');
 	if ($have_grep) {
 		print <<EOT;
 <dt><b>grep</b></dt>
 <dd>All files in the currently selected tree (HEAD unless you are explicitly browsing
-    a different one) are searched for the given
-<a href="http://en.wikipedia.org/wiki/Regular_expression">regular expression</a>
-(POSIX extended) and the matches are listed. On large
-trees, this search can take a while and put some strain on the server, so please use it with
-some consideration.</dd>
+    a different one) are searched for the given pattern. On large trees, this search can take
+a while and put some strain on the server, so please use it with some consideration. Note that
+due to git-grep peculiarity, currently if regexp mode is turned off, the matches are
+case-sensitive.</dd>
 EOT
 	}
 	print <<EOT;
 <dt><b>author</b></dt>
-<dd>Name and e-mail of the change author and date of birth of the patch will be scanned for the given string.</dd>
+<dd>Name and e-mail of the change author and date of birth of the patch will be scanned for the given pattern.</dd>
 <dt><b>committer</b></dt>
-<dd>Name and e-mail of the committer and date of commit will be scanned for the given string.</dd>
+<dd>Name and e-mail of the committer and date of commit will be scanned for the given pattern.</dd>
 EOT
 	my ($have_pickaxe) = gitweb_check_feature('pickaxe');
 	if ($have_pickaxe) {

@@ -4952,7 +4967,8 @@ EOT
 <dt><b>pickaxe</b></dt>
 <dd>All commits that caused the string to appear or disappear from any file (changes that
 added, removed or "modified" the string) will be listed. This search can take a while and
-takes a lot of strain on the server, so please use it wisely.</dd>
+takes a lot of strain on the server, so please use it wisely. Note that since you may be
+interested even in changes just changing the case as well, this search is case sensitive.</dd>
 EOT
 	}
 	print "</dl>\n";