diff --git a/src/backend/utils/adt/varlena.c b/src/backend/utils/adt/varlena.c
index 1904c116080..93a3ba11dc0 100644
--- a/src/backend/utils/adt/varlena.c
+++ b/src/backend/utils/adt/varlena.c
@@ -2905,11 +2905,12 @@ byteaGetBit(PG_FUNCTION_ARGS)
 
 	len = VARSIZE_ANY_EXHDR(v);
 
-	if (n < 0 || n >= len * 8)
+	/* Do comparison arithmetic in int64 in case len exceeds INT_MAX/8 */
+	if (n < 0 || n >= (int64) len * 8)
 		ereport(ERROR,
 				(errcode(ERRCODE_ARRAY_SUBSCRIPT_ERROR),
 				 errmsg("index %d out of valid range, 0..%d",
-						n, len * 8 - 1)));
+						n, (int) Min((int64) len * 8 - 1, INT_MAX))));
 
 	byteNo = n / 8;
 	bitNo = n % 8;
@@ -2984,11 +2985,12 @@ byteaSetBit(PG_FUNCTION_ARGS)
 
 	len = VARSIZE(v) - VARHDRSZ;
 
-	if (n < 0 || n >= len * 8)
+	/* Do comparison arithmetic in int64 in case len exceeds INT_MAX/8 */
+	if (n < 0 || n >= (int64) len * 8)
 		ereport(ERROR,
 				(errcode(ERRCODE_ARRAY_SUBSCRIPT_ERROR),
 				 errmsg("index %d out of valid range, 0..%d",
-						n, len * 8 - 1)));
+						n, (int) Min((int64) len * 8 - 1, INT_MAX))));
 
 	byteNo = n / 8;
 	bitNo = n % 8;
diff --git a/src/test/regress/expected/strings.out b/src/test/regress/expected/strings.out
index 8e7470d1cbb..7ce7dc7b71a 100644
--- a/src/test/regress/expected/strings.out
+++ b/src/test/regress/expected/strings.out
@@ -1432,6 +1432,83 @@ select md5('12345678901234567890123456789012345678901234567890123456789012345678
  t
 (1 row)
 
+--
+-- encode/decode
+--
+SET bytea_output TO hex;
+SELECT encode('\x1234567890abcdef00', 'hex');
+       encode       
+--------------------
+ 1234567890abcdef00
+(1 row)
+
+SELECT decode('1234567890abcdef00', 'hex');
+        decode        
+----------------------
+ \x1234567890abcdef00
+(1 row)
+
+SELECT encode(('\x' || repeat('1234567890abcdef0001', 7))::bytea, 'base64');
+                                    encode                                    
+------------------------------------------------------------------------------
+ EjRWeJCrze8AARI0VniQq83vAAESNFZ4kKvN7wABEjRWeJCrze8AARI0VniQq83vAAESNFZ4kKvN+
+ 7wABEjRWeJCrze8AAQ==
+(1 row)
+
+SELECT decode(encode(('\x' || repeat('1234567890abcdef0001', 7))::bytea,
+                     'base64'), 'base64');
+                                                                     decode                                                                     
+------------------------------------------------------------------------------------------------------------------------------------------------
+ \x1234567890abcdef00011234567890abcdef00011234567890abcdef00011234567890abcdef00011234567890abcdef00011234567890abcdef00011234567890abcdef0001
+(1 row)
+
+SELECT encode('\x1234567890abcdef00', 'escape');
+           encode            
+-----------------------------
+ \x124Vx\220\253\315\357\000
+(1 row)
+
+SELECT decode(encode('\x1234567890abcdef00', 'escape'), 'escape');
+        decode        
+----------------------
+ \x1234567890abcdef00
+(1 row)
+
+--
+-- get_bit/set_bit etc
+--
+SELECT get_bit('\x1234567890abcdef00'::bytea, 43);
+ get_bit 
+---------
+       1
+(1 row)
+
+SELECT get_bit('\x1234567890abcdef00'::bytea, 99);  -- error
+ERROR:  index 99 out of valid range, 0..71
+SELECT set_bit('\x1234567890abcdef00'::bytea, 43, 0);
+       set_bit        
+----------------------
+ \x1234567890a3cdef00
+(1 row)
+
+SELECT set_bit('\x1234567890abcdef00'::bytea, 99, 0);  -- error
+ERROR:  index 99 out of valid range, 0..71
+SELECT get_byte('\x1234567890abcdef00'::bytea, 3);
+ get_byte 
+----------
+      120
+(1 row)
+
+SELECT get_byte('\x1234567890abcdef00'::bytea, 99);  -- error
+ERROR:  index 99 out of valid range, 0..8
+SELECT set_byte('\x1234567890abcdef00'::bytea, 7, 11);
+       set_byte       
+----------------------
+ \x1234567890abcd0b00
+(1 row)
+
+SELECT set_byte('\x1234567890abcdef00'::bytea, 99, 11);  -- error
+ERROR:  index 99 out of valid range, 0..8
 --
 -- test behavior of escape_string_warning and standard_conforming_strings options
 --
@@ -1518,6 +1595,7 @@ select 'a\\bcd' as f1, 'a\\b\'cd' as f2, 'a\\b\'''cd' as f3, 'abcd\\'   as f4, '
 --
 -- Additional string functions
 --
+SET bytea_output TO escape;
 SELECT initcap('hi THOMAS');
   initcap  
 -----------
diff --git a/src/test/regress/sql/strings.sql b/src/test/regress/sql/strings.sql
index 5e39458bd22..2d93d2a36e2 100644
--- a/src/test/regress/sql/strings.sql
+++ b/src/test/regress/sql/strings.sql
@@ -492,6 +492,31 @@ select md5('ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789'::byt
 
 select md5('12345678901234567890123456789012345678901234567890123456789012345678901234567890'::bytea) = '57edf4a22be3c955ac49da2e2107b67a' AS "TRUE";
 
+--
+-- encode/decode
+--
+SET bytea_output TO hex;
+
+SELECT encode('\x1234567890abcdef00', 'hex');
+SELECT decode('1234567890abcdef00', 'hex');
+SELECT encode(('\x' || repeat('1234567890abcdef0001', 7))::bytea, 'base64');
+SELECT decode(encode(('\x' || repeat('1234567890abcdef0001', 7))::bytea,
+                     'base64'), 'base64');
+SELECT encode('\x1234567890abcdef00', 'escape');
+SELECT decode(encode('\x1234567890abcdef00', 'escape'), 'escape');
+
+--
+-- get_bit/set_bit etc
+--
+SELECT get_bit('\x1234567890abcdef00'::bytea, 43);
+SELECT get_bit('\x1234567890abcdef00'::bytea, 99);  -- error
+SELECT set_bit('\x1234567890abcdef00'::bytea, 43, 0);
+SELECT set_bit('\x1234567890abcdef00'::bytea, 99, 0);  -- error
+SELECT get_byte('\x1234567890abcdef00'::bytea, 3);
+SELECT get_byte('\x1234567890abcdef00'::bytea, 99);  -- error
+SELECT set_byte('\x1234567890abcdef00'::bytea, 7, 11);
+SELECT set_byte('\x1234567890abcdef00'::bytea, 99, 11);  -- error
+
 --
 -- test behavior of escape_string_warning and standard_conforming_strings options
 --
@@ -526,6 +551,7 @@ select 'a\\bcd' as f1, 'a\\b\'cd' as f2, 'a\\b\'''cd' as f3, 'abcd\\'   as f4, '
 --
 -- Additional string functions
 --
+SET bytea_output TO escape;
 
 SELECT initcap('hi THOMAS');