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authorTom Lane <tgl@sss.pgh.pa.us>2023-09-18 14:27:47 -0400
committerTom Lane <tgl@sss.pgh.pa.us>2023-09-18 14:27:47 -0400
commitec693a3f304cf91c717c0fe07abcd4185952fde5 (patch)
tree628eabb3608d04514c134567d31aaab0b7d59e87 /doc/src
parent53630f12d39b9c5d98abb7bae4818715306422ed (diff)
Don't crash if cursor_to_xmlschema is used on a non-data-returning Portal.
cursor_to_xmlschema() assumed that any Portal must have a tupDesc, which is not so. Add a defensive check. It's plausible that this mistake occurred because of the rather poorly chosen name of the lookup function SPI_cursor_find(), which in such cases is returning something that isn't very much like a cursor. Add some documentation to try to forestall future errors of the same ilk. Report and patch by Boyu Yang (docs changes by me). Back-patch to all supported branches. Discussion: https://postgr.es/m/dd343010-c637-434c-a8cb-418f53bda3b8.yangboyu.yby@alibaba-inc.com
Diffstat (limited to 'doc/src')
-rw-r--r--doc/src/sgml/spi.sgml13
1 files changed, 13 insertions, 0 deletions
diff --git a/doc/src/sgml/spi.sgml b/doc/src/sgml/spi.sgml
index 16c3ab71e85..47f4b5b4317 100644
--- a/doc/src/sgml/spi.sgml
+++ b/doc/src/sgml/spi.sgml
@@ -2727,6 +2727,19 @@ Portal SPI_cursor_find(const char * <parameter>name</parameter>)
<symbol>NULL</symbol> if none was found
</para>
</refsect1>
+
+ <refsect1>
+ <title>Notes</title>
+
+ <para>
+ Beware that this function can return a <type>Portal</type> object
+ that does not have cursor-like properties; for example it might not
+ return tuples. If you simply pass the <type>Portal</type> pointer
+ to other SPI functions, they can defend themselves against such
+ cases, but caution is appropriate when directly inspecting
+ the <type>Portal</type>.
+ </para>
+ </refsect1>
</refentry>
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