t9300: factor out portable "head -c" replacement

diff --git a/git-cvsimport.perl b/git-cvsimport.perl
index 82ecb0343a3864d1db0b066749d2087c11f689e7..1e4e65a45d16cfcc5a36e6855216e9be8fe0e0b4 100755 (executable)
--- a/git-cvsimport.perl
+++ b/git-cvsimport.perl
@@ -921,7 +921,7 @@ sub commit {
                # (See check_refname_component in refs.c.)
                1 while $xtag =~ s/
                        (?: \.\.        # Tag cannot contain '..'.
-                       |   \@{         # Tag cannot contain '@{'.
+                       |   \@\{        # Tag cannot contain '@{'.
                        | ^ -           # Tag cannot begin with '-'.
                        |   \.lock $    # Tag cannot end with '.lock'.
                        | ^ \.          # Tag cannot begin...