update_fix_d7_block_deltas() should silently succeed if block deltas have already been migrated.

The problem occurs on migrated themes which already exists in Drupal 7, like "Seven" or others.

I fixed it by removing the old hardcoded deltas from the "block" table, like records where column "delta" has values like "0", "1", etc., which belong to the modules "print", "print_mail" or "print_pdf" and had already "new" deltas by name. After that update.php completed successfully.

The reported duplicated keys have to be interpreted in the following way, e.g "seven-print-print-links" whereby "seven" is the theme, "print" the effecitive module and "print-links" the block delta.

May be the error is not really related to the module "print" but possibly to the core function "update_fix_d7_block_deltas".

No, in my opinion nothing is fixed yet.

I've just described a workaround for the print module how to migrate a site from D6 to D7 and what is causing the problem. It may be possible that there is a bug in the core function "update_fix_d7_block_deltas" which used to perform this block delta conversions.

See also #6.

No, not anymore. But comment #3 maybe of help.

I thought I had given enough details why these errors are thrown during a migration of a D6 site.

However, here are dumps of the relevant data from a D6 "blocks" and D7 "block" table:

D6 "blocks" table:

mysql> select * from igs_intra_blocks where module like 'print%' and theme='seven';
+-----+------------+-------+-------+--------+--------+---------+--------+----------+------------+-------+-------+-------+
| bid | module     | delta | theme | status | weight | region  | custom | throttle | visibility | pages | title | cache |
+-----+------------+-------+-------+--------+--------+---------+--------+----------+------------+-------+-------+-------+
| 983 | print      | 0     | seven |      0 |    -36 | content |      0 |        0 |          0 |       |       |     4 |
| 974 | print      | 1     | seven |      0 |    -45 | content |      0 |        0 |          0 |       |       |     8 |
| 971 | print_mail | 0     | seven |      0 |    -48 | content |      0 |        0 |          0 |       |       |     8 |
| 973 | print_pdf  | 0     | seven |      0 |    -46 | content |      0 |        0 |          0 |       |       |     8 |
+-----+------------+-------+-------+--------+--------+---------+--------+----------+------------+-------+-------+-------+

D7 "block" table:

mysql> select * from igs_intra_block where module like 'print%' and theme='seven';
+------+------------+----------------+-------+--------+--------+--------+--------+----------+------------+-------+-------+-------+-----------+
| bid  | module     | delta          | theme | status | weight | region | custom | throttle | visibility | pages | title | cache | i18n_mode |
+------+------------+----------------+-------+--------+--------+--------+--------+----------+------------+-------+-------+-------+-----------+
| 1572 | print      | print-links    | seven |      0 |      0 | -1     |      0 |        0 |          0 |       |       |     4 |         0 |
| 1573 | print      | print-top      | seven |      0 |      0 | -1     |      0 |        0 |          0 |       |       |     8 |         0 |
| 1185 | print_mail | print_mail-top | seven |      0 |      0 | -1     |      0 |        0 |          0 |       |       |     8 |         0 |
| 1186 | print_pdf  | print_pdf-top  | seven |      0 |      0 | -1     |      0 |        0 |          0 |       |       |     8 |         0 |
+------+------------+----------------+-------+--------+--------+--------+--------+----------+------------+-------+-------+-------+-----------+

The key information is:

The job of the core function "update_fix_d7_block_deltas" is to convert the data in column 'delta' into a D7 compatible format. But the function fails when the to be migrated "block deltas" do already exist in D7; i.e. when the contributed module is already installed in D7 and both installation have also the same theme installed. Then a clash occurs, since the D6 numerical "block deltas" are about to be converted to D7 "block deltas" with identical names/IDs.

In my opinion "update_fix_d7_block_deltas" should check this and skip any possible duplicates.

I hope this helps.

@bfroehle, you're welcome.

No, the scenario was a little bit different. I migrated the site as described in the Drupal 7 Upgrade Guide. The Print PDF module was already installed on the D6 site. After installation of Drupal 7 I migrated module by module and ran update.php immediately once a module was enabled. And during the migration of the Print PDF module the reported errors were displayed.

So I see no way to avoid this issue in this context. Maybe one other possible way to avoid this is not to have the same themes installed which have enabled blocks of such a module.

And the third way of course is, just to ignore any possible duplicate keys. And instead of throwing error messages just showing/logging a warning message.