Clean up sloppy coding in publicationcmds.c's OpenTableList().

Remove dead code (which would be incorrect if it weren't dead),
per report from Pan Bian.  Add a CHECK_FOR_INTERRUPTS in the
inner loop over child relations, because there's little point
in having one in the outer loop if there's not one here too.
Minor stylistic adjustments and comment improvements.

Seems to be aboriginal to this code (cf commit 665d1fad9).
Back-patch to v10 where that came in, not because any of this
is significant, but just to keep the branches looking similar.

Discussion: https://postgr.es/m/15539-06d00ef6b1e2e1bb@postgresql.org

diff --git a/src/backend/commands/publicationcmds.c b/src/backend/commands/publicationcmds.c
index f298d3d381c33a66405cd5cc0eb09a8c14d05bfe..8f324298b596d058c9518c20c8ef4661ea811f5c 100644 (file)
--- a/src/backend/commands/publicationcmds.c
+++ b/src/backend/commands/publicationcmds.c
@@ -470,7 +470,7 @@ RemovePublicationRelById(Oid proid)
 }
 
 /*
- * Open relations based on provided by RangeVar list.
+ * Open relations specified by a RangeVar list.
  * The returned tables are locked in ShareUpdateExclusiveLock mode.
  */
 static List *
@@ -485,11 +485,12 @@ OpenTableList(List *tables)
     */
    foreach(lc, tables)
    {
-       RangeVar   *rv = lfirst(lc);
-       Relation    rel;
+       RangeVar   *rv = castNode(RangeVar, lfirst(lc));
        bool        recurse = rv->inh;
+       Relation    rel;
        Oid         myrelid;
 
+       /* Allow query cancel in case this takes a long time */
        CHECK_FOR_INTERRUPTS();
 
        rel = heap_openrv(rv, ShareUpdateExclusiveLock);
@@ -507,13 +508,15 @@ OpenTableList(List *tables)
            heap_close(rel, ShareUpdateExclusiveLock);
            continue;
        }
+
        rels = lappend(rels, rel);
        relids = lappend_oid(relids, myrelid);
 
+       /* Add children of this rel, if requested */
        if (recurse)
        {
-           ListCell   *child;
            List       *children;
+           ListCell   *child;
 
            children = find_all_inheritors(myrelid, ShareUpdateExclusiveLock,
                                           NULL);
@@ -522,18 +525,15 @@ OpenTableList(List *tables)
            {
                Oid         childrelid = lfirst_oid(child);
 
-               if (list_member_oid(relids, childrelid))
-                   continue;
+               /* Allow query cancel in case this takes a long time */
+               CHECK_FOR_INTERRUPTS();
 
                /*
                 * Skip duplicates if user specified both parent and child
                 * tables.
                 */
                if (list_member_oid(relids, childrelid))
-               {
-                   heap_close(rel, ShareUpdateExclusiveLock);
                    continue;
-               }
 
                /* find_all_inheritors already got lock */
                rel = heap_open(childrelid, NoLock);