From fd0d0d731392bcb2fc154cb18a292909ca301713 Mon Sep 17 00:00:00 2001
From: Ayush Tiwari <ayushtiwari.slg01@gmail.com>
Date: Fri, 21 Aug 2026 15:37:01 +0530
Subject: [PATCH v1] Fix internal errors reachable from SQL

currtid_for_view() ended with an elog() when it could not resolve the
view's ctid column to a base relation, which happens for example when
the view groups by ctid.  Ordinary SQL can reach that, so it should not
be reported as XX000 (internal_error).  The other unsupported-view
checks in the same function report ERRCODE_FEATURE_NOT_SUPPORTED, so
match them.  (bug #19631)

While looking for other instances of the same problem, a few more
errors reachable from SQL turned out to have no error code:

* varlena.c: unicode_assigned() rejects non-UTF8 server encodings;
  unicode_normalize() and formatting.c use ERRCODE_SYNTAX_ERROR for the
  same restriction, so match them.

* pg_controldata.c: the pg_control_*() functions raise a control file
  CRC mismatch, which is ERRCODE_DATA_CORRUPTED.

* gist.c: an inner tuple left invalid by a pre-9.1 crash is a corrupt
  index, so use ERRCODE_INDEX_CORRUPTED, like the checks in gistutil.c.

* collationcmds.c: refusing ALTER COLLATION ... REFRESH VERSION for the
  default collation is ERRCODE_WRONG_OBJECT_TYPE.

No messages change, so there is no expected output churn.

Author: Ayush Tiwari <ayushtiwari.slg01@gmail.com>
Bug: #19631
Reported-by: Zheng Wang <hackerzheng666@gmail.com>
Reported-by: Yanjie Zhao
Reported-by: Yiyang Liu
Discussion: https://postgr.es/m/19631-b443dd6cd8d4e40b@postgresql.org
---
 src/backend/access/gist/gist.c          |  3 ++-
 src/backend/commands/collationcmds.c    |  3 ++-
 src/backend/utils/adt/tid.c             |  4 +++-
 src/backend/utils/adt/varlena.c         |  3 ++-
 src/backend/utils/misc/pg_controldata.c | 12 ++++++++----
 5 files changed, 17 insertions(+), 8 deletions(-)

diff --git a/src/backend/access/gist/gist.c b/src/backend/access/gist/gist.c
index 8565e225be7..44597793433 100644
--- a/src/backend/access/gist/gist.c
+++ b/src/backend/access/gist/gist.c
@@ -762,7 +762,8 @@ gistdoinsert(Relation r, IndexTuple itup, Size freespace,
 			 */
 			if (GistTupleIsInvalid(idxtuple))
 				ereport(ERROR,
-						(errmsg("index \"%s\" contains an inner tuple marked as invalid",
+						(errcode(ERRCODE_INDEX_CORRUPTED),
+						 errmsg("index \"%s\" contains an inner tuple marked as invalid",
 								RelationGetRelationName(r)),
 						 errdetail("This is caused by an incomplete page split at crash recovery before upgrading to PostgreSQL 9.1."),
 						 errhint("Please REINDEX it.")));
diff --git a/src/backend/commands/collationcmds.c b/src/backend/commands/collationcmds.c
index cfa0e4610d9..92faa60a750 100644
--- a/src/backend/commands/collationcmds.c
+++ b/src/backend/commands/collationcmds.c
@@ -443,7 +443,8 @@ AlterCollation(AlterCollationStmt *stmt)
 
 	if (collOid == DEFAULT_COLLATION_OID)
 		ereport(ERROR,
-				(errmsg("cannot refresh version of default collation"),
+				(errcode(ERRCODE_WRONG_OBJECT_TYPE),
+				 errmsg("cannot refresh version of default collation"),
 		/* translator: %s is an SQL command */
 				 errhint("Use %s instead.",
 						 "ALTER DATABASE ... REFRESH COLLATION VERSION")));
diff --git a/src/backend/utils/adt/tid.c b/src/backend/utils/adt/tid.c
index a97873f91ba..9b2cca0db4d 100644
--- a/src/backend/utils/adt/tid.c
+++ b/src/backend/utils/adt/tid.c
@@ -432,7 +432,9 @@ currtid_for_view(Relation viewrel, const ItemPointerData *tid)
 			break;
 		}
 	}
-	elog(ERROR, "currtid cannot handle this view");
+	ereport(ERROR,
+			errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+			errmsg("currtid cannot handle this view"));
 	return NULL;
 }
 
diff --git a/src/backend/utils/adt/varlena.c b/src/backend/utils/adt/varlena.c
index a09a9e5d5bb..823381073b8 100644
--- a/src/backend/utils/adt/varlena.c
+++ b/src/backend/utils/adt/varlena.c
@@ -5482,7 +5482,8 @@ unicode_assigned(PG_FUNCTION_ARGS)
 
 	if (GetDatabaseEncoding() != PG_UTF8)
 		ereport(ERROR,
-				(errmsg("Unicode categorization can only be performed if server encoding is UTF8")));
+				(errcode(ERRCODE_SYNTAX_ERROR),
+				 errmsg("Unicode categorization can only be performed if server encoding is UTF8")));
 
 	/* convert to char32_t */
 	size = pg_mbstrlen_with_len(VARDATA_ANY(input), VARSIZE_ANY_EXHDR(input));
diff --git a/src/backend/utils/misc/pg_controldata.c b/src/backend/utils/misc/pg_controldata.c
index ab74d169c96..4fb56aa413c 100644
--- a/src/backend/utils/misc/pg_controldata.c
+++ b/src/backend/utils/misc/pg_controldata.c
@@ -47,7 +47,8 @@ pg_control_system(PG_FUNCTION_ARGS)
 	LWLockRelease(ControlFileLock);
 	if (!crc_ok)
 		ereport(ERROR,
-				(errmsg("calculated CRC checksum does not match value stored in file")));
+				(errcode(ERRCODE_DATA_CORRUPTED),
+				 errmsg("calculated CRC checksum does not match value stored in file")));
 
 	values[0] = Int32GetDatum(ControlFile->pg_control_version);
 	nulls[0] = false;
@@ -87,7 +88,8 @@ pg_control_checkpoint(PG_FUNCTION_ARGS)
 	LWLockRelease(ControlFileLock);
 	if (!crc_ok)
 		ereport(ERROR,
-				(errmsg("calculated CRC checksum does not match value stored in file")));
+				(errcode(ERRCODE_DATA_CORRUPTED),
+				 errmsg("calculated CRC checksum does not match value stored in file")));
 
 	/*
 	 * Calculate name of the WAL file containing the latest checkpoint's REDO
@@ -184,7 +186,8 @@ pg_control_recovery(PG_FUNCTION_ARGS)
 	LWLockRelease(ControlFileLock);
 	if (!crc_ok)
 		ereport(ERROR,
-				(errmsg("calculated CRC checksum does not match value stored in file")));
+				(errcode(ERRCODE_DATA_CORRUPTED),
+				 errmsg("calculated CRC checksum does not match value stored in file")));
 
 	values[0] = LSNGetDatum(ControlFile->minRecoveryPoint);
 	nulls[0] = false;
@@ -225,7 +228,8 @@ pg_control_init(PG_FUNCTION_ARGS)
 	LWLockRelease(ControlFileLock);
 	if (!crc_ok)
 		ereport(ERROR,
-				(errmsg("calculated CRC checksum does not match value stored in file")));
+				(errcode(ERRCODE_DATA_CORRUPTED),
+				 errmsg("calculated CRC checksum does not match value stored in file")));
 
 	values[0] = Int32GetDatum(ControlFile->maxAlign);
 	nulls[0] = false;

base-commit: a1bb92fb250a7ff94a13a0e7ac784f88ccc0c402
-- 
2.34.1

