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 479ae8f96db17ff30270e391884338f4d604d57d..fc3a4c19e6533c45b11fbb020ed17720bf1fabc8 100644 (file)
--- a/src/backend/commands/publicationcmds.c
+++ b/src/backend/commands/publicationcmds.c
@@ -121,7 +121,12 @@ 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 458418a249dda43a68340d2157fc341eec1d783f..9ee8949e0406d34b65c41524c23af2ec620b5d15 100644 (file)
--- a/src/backend/replication/pgoutput/pgoutput.c
+++ b/src/backend/replication/pgoutput/pgoutput.c
@@ -346,7 +346,11 @@ 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),