From: Jeff King <peff@peff.net>
Date: Thu, 23 Jul 2009 11:09:29 +0000 (-0400)
Subject: send-email: detect cycles in alias expansion
X-Git-Tag: v1.6.4-rc3~9^2
X-Git-Url: https://git.tokkee.org/?a=commitdiff_plain;h=302e04ea4d0c0414cedd716de882fa3dbe3480eb;p=git.git

send-email: detect cycles in alias expansion

With the previous code, an alias cycle like:

  $ echo 'alias a b' >aliases
  $ echo 'alias b a' >aliases
  $ git config sendemail.aliasesfile aliases
  $ git config sendemail.aliasfiletype mutt

would put send-email into an infinite loop. This patch
detects the situation and complains to the user.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---

diff --git a/git-send-email.perl b/git-send-email.perl
index cccbf4517..f299c2dba 100755
--- a/git-send-email.perl
+++ b/git-send-email.perl
@@ -655,13 +655,17 @@ if (!@to) {
 }
 
 sub expand_aliases {
-	my @cur = @_;
-	my @last;
-	do {
-		@last = @cur;
-		@cur = map { $aliases{$_} ? @{$aliases{$_}} : $_ } @last;
-	} while (join(',',@cur) ne join(',',@last));
-	return @cur;
+	return map { expand_one_alias($_) } @_;
+}
+
+my %EXPANDED_ALIASES;
+sub expand_one_alias {
+	my $alias = shift;
+	if ($EXPANDED_ALIASES{$alias}) {
+		die "fatal: alias '$alias' expands to itself\n";
+	}
+	local $EXPANDED_ALIASES{$alias} = 1;
+	return $aliases{$alias} ? expand_aliases(@{$aliases{$alias}}) : $alias;
 }
 
 @to = expand_aliases(@to);