postgres.git / summary / log / commit / refs

commit    17082a88eadfca79b50c04c5a78a2c38ee4f5d9c
Author:   Peter Eisentraut <peter_e@gmx.net>
Date:     Tue Jun 13 12:49:41 2017 +0000

    Prevent copying default collation
    
    This will not have the desired effect and might lead to crashes when the
    copied collation is used.
    
    Reported-by: Tom Lane <tgl@sss.pgh.pa.us>


 src/backend/commands/collationcmds.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/src/backend/commands/collationcmds.c b/src/backend/commands/collationcmds.c
index ab702c2479c..91b65b174d3 100644
--- a/src/backend/commands/collationcmds.c
+++ b/src/backend/commands/collationcmds.c
@@ -120,6 +120,18 @@ DefineCollation(ParseState *pstate, List *names, List *parameters, bool if_not_e
 		collprovider = ((Form_pg_collation) GETSTRUCT(tp))->collprovider;
 
 		ReleaseSysCache(tp);
+
+		/*
+		 * Copying the "default" collation is not allowed because most code
+		 * checks for DEFAULT_COLLATION_OID instead of COLLPROVIDER_DEFAULT,
+		 * and so having a second collation with COLLPROVIDER_DEFAULT would
+		 * not work and potentially confuse or crash some code.  This could be
+		 * fixed with some legwork.
+		 */
+		if (collprovider == COLLPROVIDER_DEFAULT)
+			ereport(ERROR,
+					(errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
+					 errmsg("collation \"default\" cannot be copied")));
 	}
 
 	if (localeEl)


[parent: 78a030a44196]