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 e288dd41cdc220934f4742555409ddb90136cac6..9347b99aa9b37ca965eaec26abe7641bcae4fadd 100644 (file)
--- a/src/backend/commands/publicationcmds.c
+++ b/src/backend/commands/publicationcmds.c
@@ -96,7 +96,12 @@ parse_publication_options(List *options,
                        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 a81215cff8654b5de44381ae605f5daf75fadfa2..e7b85fcdddf9c5a47bb77326351b3736ebd6c7b4 100644 (file)
--- a/src/backend/replication/pgoutput/pgoutput.c
+++ b/src/backend/replication/pgoutput/pgoutput.c
@@ -220,7 +220,11 @@ 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),