Add __attribute__ decorations for printf format checking to the places that
were missing them. Fix the resulting warnings. Add
-Wmissing-format-attribute to the standard set of warnings for GCC, so these
don't happen again.
The warning fixes here are relatively harmless. The one serious problem
discovered by this was already committed earlier in
cf15fb5cab.
Add errno-based output to error messages where appropriate, reformat
blocks to about 72 characters per line, use spaces instead of tabs for
indentation, and other style adjustments.
If someone removes the 'postgres' database from the old cluster and the
new cluster has a 'postgres' database, the number of databases will not
match. We actually could upgrade such a setup, but it would violate the
1-to-1 mapping of database counts, so we throw an error instead.
Previously they got an error during the upgrade, and not at the check
stage; PG 9.0.4 does the same.
up relations, but rather order old/new relations and use the same array
index value for both. This should speed up pg_upgrade for databases
with many relations.
pointers, which simplifies the code. This was not possible in 9.0 because
everything was in a single nested struct, but is possible now.
Per suggestion from Tom.
cmp parameter for pg_scandir(). The code failed to support this anyway
for Sun/Windows, so pretending we could accept a parameter other than
NULL was just asking for trouble.
