Fix issue with EVENT TRIGGERS and ALTER PUBLICATION

When processing the "publish" options of an ALTER PUBLICATION command,
we call SplitIdentifierString() to split the options into a List of
strings.  Since SplitIdentifierString() modifies the delimiter
character and puts NULs in their place, this would overwrite the memory
of the AlterPublicationStmt.  Later in AlterPublicationOptions(), the
modified AlterPublicationStmt is copied for event triggers, which would
result in the event trigger only seeing the first "publish" option
rather than all options that were specified in the command.

To fix this, make a copy of the string before passing to
SplitIdentifierString().

Here we also adjust a similar case in the pgoutput plugin.  There's no
known issues caused by SplitIdentifierString() here, so this is being
done out of paranoia.

Thanks to Henson Choi for putting together an example case showing the
ALTER PUBLICATION issue.

Author: sunil s <sunilfeb26@gmail.com>
Reviewed-by: Henson Choi <assam258@gmail.com>
Reviewed-by: zengman <zengman@halodbtech.com>
Backpatch-through: 14

diff --git a/src/backend/commands/publicationcmds.c b/src/backend/commands/publicationcmds.c
index 473c72eae515f074ab884ec222b5cffc5aaa5f69..b9bd33b252e64629d4c886d5be9a623f080c9941 100644 (file)
--- a/src/backend/commands/publicationcmds.c
+++ b/src/backend/commands/publicationcmds.c
@@ -122,7 +122,12 @@ parse_publication_options(ParseState *pstate,
                        pubactions->pubtruncate = false;
 
                        *publish_given = true;
-                       publish = defGetString(defel);
+
+                       /*
+                        * SplitIdentifierString destructively modifies its input, so make
+                        * a copy so we don't modify the memory of the executing statement
+                        */
+                       publish = pstrdup(defGetString(defel));
 
                        if (!SplitIdentifierString(publish, ',', &publish_list))
                                ereport(ERROR,

diff --git a/src/backend/replication/pgoutput/pgoutput.c b/src/backend/replication/pgoutput/pgoutput.c
index f3acc64c45158936b770da4c099fb22bd351de7d..7ae31b0acce92a6e6ea7731f9e1bd7f7c0b01da7 100644 (file)
--- a/src/backend/replication/pgoutput/pgoutput.c
+++ b/src/backend/replication/pgoutput/pgoutput.c
@@ -342,7 +342,11 @@ parse_output_parameters(List *options, PGOutputData *data)
                                                 errmsg("conflicting or redundant options")));
                        publication_names_given = true;
 
-                       if (!SplitIdentifierString(strVal(defel->arg), ',',
+                       /*
+                        * Pass a copy of the DefElem->arg since SplitIdentifierString
+                        * modifies its input.
+                        */
+                       if (!SplitIdentifierString(pstrdup(strVal(defel->arg)), ',',
                                                                           &data->publication_names))
                                ereport(ERROR,
                                                (errcode(ERRCODE_INVALID_NAME),