pgsql: Fix pg_dump assertion failure when dumping pg_catalog.

On 22.08.23 22:08, Jeff Davis wrote:

Fix pg_dump assertion failure when dumping pg_catalog.

Commit 396d348b04 did not account for the default collation.

Also, use pg_log_warning() instead of Assert().

Looking at this:

pg_log_warning("invalid collation \"%s\"", qcollname);

qcollname is already a quoted identifier, so this message would be
doubly quoted. Maybe you should use collinfo->dobj.name in the messages.

Also, for

pg_fatal("unrecognized collation provider '%c'", collprovider[0]);

use double quotes.

On 22.08.23 22:08, Jeff Davis wrote:

Fix pg_dump assertion failure when dumping pg_catalog.

Commit 396d348b04 did not account for the default collation.

Also, use pg_log_warning() instead of Assert().

Discussion: /messages/by-id/ce071503fee88334aa70f360e6e4ea14d48305ee.camel@j-davis.com
Reviewed-by: Michael Paquier
Backpatch-through: 15

I have another question about this patch. The original issue was that
it would trigger an Assert() inside pg_dump when some columns in
pg_collation were null that were not expected. This patch now contains
code like

             appendPQExpBufferStr(q, ", lc_collate = ");
-           appendStringLiteralAH(q, collcollate, fout);
+           appendStringLiteralAH(q, collcollate ? collcollate : "", fout);
             appendPQExpBufferStr(q, ", lc_ctype = ");
-           appendStringLiteralAH(q, collctype, fout);
+           appendStringLiteralAH(q, collctype ? collctype : "", fout);

which would produce pg_dump output like

CREATE COLLATION ... (provider = libc, lc_collate = , lc_ctype = );

which is not valid syntax.

Peter Eisentraut <peter@eisentraut.org> writes:

I have another question about this patch. The original issue was that
it would trigger an Assert() inside pg_dump when some columns in
pg_collation were null that were not expected. This patch now contains
code like

appendPQExpBufferStr(q, ", lc_collate = ");
-           appendStringLiteralAH(q, collcollate, fout);
+           appendStringLiteralAH(q, collcollate ? collcollate : "", fout);
appendPQExpBufferStr(q, ", lc_ctype = ");
-           appendStringLiteralAH(q, collctype, fout);
+           appendStringLiteralAH(q, collctype ? collctype : "", fout);

which would produce pg_dump output like

CREATE COLLATION ... (provider = libc, lc_collate = , lc_ctype = );

which is not valid syntax.

How so? appendStringLiteral adds quotes around what it's given,
empty string or no.

The receiving server might or might not like those parameters
semantically, but the syntax should be ok.

regards, tom lane