Adjust bytea get_bit/set_bit to use int8 not int4 for bit numbering.

Since the existing bit number argument can't exceed INT32_MAX, it's
not possible for these functions to manipulate bits beyond the first
256MB of a bytea value.  Lift that restriction by redeclaring the
bit number arguments as int8 (which requires a catversion bump,
hence is not back-patchable).

The similarly-named functions for bit/varbit don't really have a
problem because we restrict those types to at most VARBITMAXLEN bits;
hence leave them alone.

While here, extend the encode/decode functions in utils/adt/encode.c
to allow dealing with values wider than 1GB.  This is not a live bug
or restriction in current usage, because no input could be more than
1GB, and since none of the encoders can expand a string more than 4X,
the result size couldn't overflow uint32.  But it might be desirable
to support more in future, so make the input length values size_t
and the potential-output-length values uint64.

Also add some test cases to improve the miserable code coverage
of these functions.

Movead Li, editorialized some by me; also reviewed by Ashutosh Bapat

Discussion: https://postgr.es/m/20200312115135445367128@highgo.ca

1 files changed, 2 insertions, 2 deletions

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index cc4a7bf8dfa..a38387b8c60 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -2905,7 +2905,7 @@ SELECT format('Testing %3$s, %2$s, %s', 'one', 'two', 'three');
         <indexterm>
          <primary>get_bit</primary>
         </indexterm>
-        <literal><function>get_bit(<parameter>bytes</parameter> <type>bytea</type>, <parameter>offset</parameter> <type>int</type>)</function></literal>
+        <literal><function>get_bit(<parameter>bytes</parameter> <type>bytea</type>, <parameter>offset</parameter> <type>bigint</type>)</function></literal>
        </entry>
        <entry><type>int</type></entry>
        <entry>
@@ -2990,7 +2990,7 @@ SELECT format('Testing %3$s, %2$s, %s', 'one', 'two', 'three');
          <primary>set_bit</primary>
         </indexterm>
         <literal><function>set_bit(<parameter>bytes</parameter> <type>bytea</type>,
-        <parameter>offset</parameter> <type>int</type>,
+        <parameter>offset</parameter> <type>bigint</type>,
         <parameter>newvalue</parameter> <type>int</type>)</function></literal>
        </entry>
        <entry><type>bytea</type></entry>