ChangeHandler: Don't hexify text columns.

As far as I understand, it doesn't make any sense to hexify text
columns; they break in many ways (you can't roundtrip the UTFs,
quote_val gets the hex quoting wrong, etc) and in any case,
the maatkit bugs about the feature are all about blob/binary
columns.

And, while a perilous excercise of genetic programming, removing
it didn't break any pt-table-sync tests, so this commit does
exactly that.

bin/pt-table-sync

@@ -3572,7 +3572,7 @@ sub make_fetch_back_query {
          map {
             my $col = $_;
             if (    $self->{hex_blob}
-                 && $tbl_struct->{type_for}->{$col} =~ m/blob|text|binary/ ) {
+                 && $tbl_struct->{type_for}->{$col} =~ m/b(?:lob|inary)/ ) {
                $col = "IF(BINARY(`$col`)='', '', CONCAT('0x', HEX(`$col`))) AS `$col`";
             }
             else {

lib/ChangeHandler.pm

@@ -496,7 +496,7 @@ sub make_fetch_back_query {
          map {
             my $col = $_;
             if (    $self->{hex_blob}
-                 && $tbl_struct->{type_for}->{$col} =~ m/blob|text|binary/ ) {
+                 && $tbl_struct->{type_for}->{$col} =~ m/b(?:lob|inary)/ ) {
                # Here we cast to binary, as otherwise, since text columns are
                # space padded, MySQL would compare ' ' and '' to be the same.
                # See https://bugs.launchpad.net/percona-toolkit/+bug/930693

t/lib/ChangeHandler.t

@@ -386,7 +386,7 @@ is(
 # #############################################################################
 $tbl_struct = {
    cols     => [qw(t)],
-   type_for => {t=>'text'},
+   type_for => {t=>'blob'},
 };
 $ch = new ChangeHandler(
    Quoter     => $q,
@@ -406,6 +406,33 @@ is(
    "Don't prepend 0x to blank blob/text column value (issue 1052)"
 );
 
+# #############################################################################
+# An update to the above bug; It should only hexify for blob and binary, not
+# for text columns; The latter not only breaks for UTF-8 data, but also
+# breaks now that hex-looking columns aren't automatically left unquoted.
+# #############################################################################
+$tbl_struct = {
+   cols     => [qw(t)],
+   type_for => {t=>'text'},
+};
+$ch = new ChangeHandler(
+   Quoter     => $q,
+   left_db    => 'test',
+   left_tbl   => 't',
+   right_db   => 'test',
+   right_tbl  => 't',
+   actions    => [ sub {} ],
+   replace    => 0,
+   queue      => 0,
+   tbl_struct => $tbl_struct,
+);
+
+is(
+   $ch->make_fetch_back_query('1=1'),
+   "SELECT `t` FROM `test`.`t` WHERE 1=1 LIMIT 1",
+   "Don't prepend 0x to blank blob/text column value (issue 1052)"
+);
+
 # #############################################################################
 
 SKIP: {