Fix for 887638: pt-query-digest prints negative byte offset

bin/pt-query-digest

@@ -492,12 +492,18 @@ sub quote_val {
 
 sub split_unquote {
    my ( $self, $db_tbl, $default_db ) = @_;
-   $db_tbl =~ s/`//g;
    my ( $db, $tbl ) = split(/[.]/, $db_tbl);
    if ( !$tbl ) {
       $tbl = $db;
       $db  = $default_db;
    }
+   for ($db, $tbl) {
+      next unless $_;
+      s/\A`//;
+      s/`\z//;
+      s/``/`/g;
+   }
+   
    return ($db, $tbl);
 }
 
@@ -6715,7 +6721,7 @@ sub event_report {
    }
 
    my $line = sprintf(
-      '# %s %d: %s QPS, %sx concurrency, ID 0x%s at byte %d ',
+      '# %s %d: %s QPS, %sx concurrency, ID 0x%s at byte %.f ',
       ($ea->{groupby} eq 'fingerprint' ? 'Query' : 'Item'),
       $args{rank} || 0,
       shorten($qps  || 0, d=>1_000),
@@ -8103,16 +8109,20 @@ $Data::Dumper::Indent    = 1;
 $Data::Dumper::Sortkeys  = 1;
 $Data::Dumper::Quotekeys = 0;
 
+local $EVAL_ERROR;
+eval {
+   require Quoter;
+};
+
 sub new {
    my ( $class, %args ) = @_;
-   my @required_args = qw(Quoter);
-   foreach my $arg ( @required_args ) {
-      die "I need a $arg argument" unless $args{$arg};
-   }
    my $self = { %args };
+   $self->{Quoter} ||= Quoter->new();
    return bless $self, $class;
 }
 
+sub Quoter { shift->{Quoter} }
+
 sub get_create_table {
    my ( $self, $dbh, $db, $tbl ) = @_;
    die "I need a dbh parameter" unless $dbh;

lib/QueryReportFormatter.pm

@@ -524,7 +524,7 @@ sub event_report {
    # First line like:
    # Query 1: 9 QPS, 0x concurrency, ID 0x7F7D57ACDD8A346E at byte 5 ________
    my $line = sprintf(
-      '# %s %d: %s QPS, %sx concurrency, ID 0x%s at byte %d ',
+      '# %s %d: %s QPS, %sx concurrency, ID 0x%s at byte %.f ',
       ($ea->{groupby} eq 'fingerprint' ? 'Query' : 'Item'),
       $args{rank} || 0,
       shorten($qps  || 0, d=>1_000),

t/lib/QueryReportFormatter.t

@@ -9,7 +9,7 @@ BEGIN {
 use strict;
 use warnings FATAL => 'all';
 use English qw(-no_match_vars);
-use Test::More tests => 45;
+use Test::More;
 
 use Data::Dumper;
 $Data::Dumper::Indent    = 1;
@@ -187,6 +187,38 @@ ok(
    'Event report'
 );
 
+{
+   # pt-query-digest prints negative byte offset
+   # https://bugs.launchpad.net/percona-toolkit/+bug/887638
+
+   # printf "%d" can't really handle large values in some systems.
+   # Given a large enough log file, it will start printing
+   # negative values. The workaround is to use %.f instead. I haven't
+   # researched what the recommended solution for this is, but
+   # it's such an uncommon case and that it's not worth the time.
+   # This bug should really only affect 32-bit machines, and even then
+   # only those were the underlaying compiler's printf("%d") coerces the
+   # argument into a signed int.
+   my $item = 'select id from users where name=?';
+   local $ea->results->{samples}->{$item}->{pos_in_log} = 1e+33;
+
+   $result = $qrf->event_report(
+      ea => $ea,
+      # "users" is here to try to cause a failure
+      select => [ qw(Query_time Lock_time Rows_sent Rows_examined ts db user users) ],
+      item    => $item,
+      rank    => 1,
+      orderby => 'Query_time',
+      reason  => 'top',
+   );
+
+   unlike(
+      $result,
+      qr/at byte -/,
+      "Bug 887638: pt-query-digest prints negative byte offset"
+   );
+}
+
 $result = $qrf->chart_distro(
    ea     => $ea,
    attrib => 'Query_time',
@@ -1570,4 +1602,5 @@ like(
    '_d() works'
 );
 ok($sb->ok(), "Sandbox servers") or BAIL_OUT(__FILE__ . " broke the sandbox");
+done_testing;
 exit;