Truncate col names to 64 chars in MockSyncStream::get_result_set_struct(). Update test sample file.

bin/pt-upgrade

@@ -8036,7 +8036,14 @@ sub pending_changes {
 
 sub get_result_set_struct {
    my ( $dbh, $sth ) = @_;
-   my @cols     = @{$sth->{NAME}};
+   my @cols     = map { 
+      my $name = $_;
+      my $name_len = length($name);
+      if ( $name_len > 64 ) {
+         $name = substr($name, ($name_len - 64), 64);
+      }
+      $name;
+   } @{$sth->{NAME}};
    my @types    = map { $dbh->type_info($_)->{TYPE_NAME} } @{$sth->{TYPE}};
    my @nullable = map { $dbh->type_info($_)->{NULLABLE} == 1 ? 1 : 0 } @{$sth->{TYPE}};
 

lib/MockSyncStream.pm

@@ -94,7 +94,17 @@ sub pending_changes {
 # uses sth attributes to return a pseudo table struct for the query's columns.
 sub get_result_set_struct {
    my ( $dbh, $sth ) = @_;
-   my @cols     = @{$sth->{NAME}};
+   my @cols     = map { 
+      my $name = $_;
+      my $name_len = length($name);
+      if ( $name_len > 64 ) {
+         # https://bugs.launchpad.net/percona-toolkit/+bug/1060774
+         # Chop off the left end because right-side data tends to be
+         # the difference, e.g. load_the_canons vs. load_the_cantos.
+         $name = substr($name, ($name_len - 64), 64);
+      }
+      $name;
+   } @{$sth->{NAME}};
    my @types    = map { $dbh->type_info($_)->{TYPE_NAME} } @{$sth->{TYPE}};
    my @nullable = map { $dbh->type_info($_)->{NULLABLE} == 1 ? 1 : 0 } @{$sth->{TYPE}};
 

t/pt-upgrade/basics.t

@@ -198,6 +198,7 @@ ok(
    no_diff(
       sub { pt_upgrade::main(@args,
          qw(--compare-results-method rows),
+         qw(--no-clear-warnings),
          "$log/004/select-func.log") },
       "$sample/004/select-func.txt",
    ),

t/pt-upgrade/samples/004/select-func.txt

@@ -0,0 +1,36 @@
+
+# Query 1: ID 0xF05C9711D543F5BF at byte 0 _______________________________
+# host1: 127.1:12345
+# host2: 127.1:12348
+# Found 0 differences in 1 samples:
+#   column counts   0
+#   column types    0
+#   column values   0
+#   row counts      0
+#   warning counts  0
+#   warning levels  0
+#   warnings        0
+#            host1 host2
+# Errors         0     0
+# Warnings       0     0
+# Query_time            
+#   sum          0     0
+#   min          0     0
+#   max          0     0
+#   avg          0     0
+#   pct_95       0     0
+#   stddev       0     0
+#   median       0     0
+# row_count             
+#   sum          1     1
+#   min          1     1
+#   max          1     1
+#   avg          1     1
+#   pct_95       1     1
+#   stddev       0     0
+#   median       1     1
+use `test`;
+SELECT (UNIX_TIMESTAMP(NOW()) - UNIX_TIMESTAMP('2012-09-16 10:16:36')) / 60, SLEEP(1)
+
+# Statistics
+# events                         1