Bug 141951: Set the max_packet_size for attachments (and bugs_fulltext) when connecting to MySQL

Patch By Max Kanat-Alexander <mkanat@bugzilla.org> r=LpSolit, a=mkanat

3 files changed, 21 insertions, 3 deletions

diff --git a/Bugzilla/Bug.pm b/Bugzilla/Bug.pm
index 95e6f6d31..0d1ec66f2 100644
--- a/Bugzilla/Bug.pm
+++ b/Bugzilla/Bug.pm
@@ -230,9 +230,6 @@ use constant UPDATE_COMMENT_COLUMNS => qw(
 # activity table.
 use constant MAX_LINE_LENGTH => 254;
 
-# Used in _check_comment(). Gives the max length allowed for a comment.
-use constant MAX_COMMENT_LENGTH => 65535;
-
 #####################################################################
 
 sub new {
diff --git a/Bugzilla/Constants.pm b/Bugzilla/Constants.pm
index 601ea52b2..c08156335 100644
--- a/Bugzilla/Constants.pm
+++ b/Bugzilla/Constants.pm
@@ -84,6 +84,7 @@ use File::Basename;
     LIST_OF_BUGS
 
     COMMENT_COLS
+    MAX_COMMENT_LENGTH
 
     CMT_NORMAL
     CMT_DUPE_OF
@@ -264,6 +265,8 @@ use constant LIST_OF_BUGS => 1;
 
 # The column length for displayed (and wrapped) bug comments.
 use constant COMMENT_COLS => 80;
+# Used in _check_comment(). Gives the max length allowed for a comment.
+use constant MAX_COMMENT_LENGTH => 65535;
 
 # The type of bug comments.
 use constant CMT_NORMAL => 0;
diff --git a/Bugzilla/DB/Mysql.pm b/Bugzilla/DB/Mysql.pm
index 2f42f9f34..601be102b 100644
--- a/Bugzilla/DB/Mysql.pm
+++ b/Bugzilla/DB/Mysql.pm
@@ -51,6 +51,11 @@ use Bugzilla::DB::Schema::Mysql;
 use List::Util qw(max);
 use Text::ParseWords;
 
+# This is how many comments of MAX_COMMENT_LENGTH we expect on a single bug.
+# In reality, you could have a LOT more comments than this, because 
+# MAX_COMMENT_LENGTH is big.
+use constant MAX_COMMENTS => 50;
+
 # This module extends the DB interface via inheritance
 use base qw(Bugzilla::DB);
 
@@ -93,6 +98,19 @@ sub new {
         }
     }
 
+    # The "comments" field of the bugs_fulltext table could easily exceed
+    # MySQL's default max_allowed_packet. Also, MySQL should never have
+    # a max_allowed_packet smaller than our max_attachment_size. However,
+    # if we've already set a max_allowed_packet in MySQL bigger than all
+    # of those, we should keep it.
+    my (undef, $current_max_allowed) = $self->selectrow_array(
+        q{SHOW VARIABLES LIKE 'max\_allowed\_packet'});
+    my $min_max_allowed_packet = MAX_COMMENTS * MAX_COMMENT_LENGTH;
+    my $max_allowed_packet = max($min_max_allowed_packet,
+                                 $current_max_allowed,
+                                 Bugzilla->params->{'maxattachmentsize'});
+    $self->do("SET SESSION max_allowed_packet = $max_allowed_packet");
+
     return $self;
 }