Fix misplaced right paren bugs in pgstatfuncs.c.

The bug would only show up if the C sockaddr structure contained
zero in the first byte for a valid address; otherwise it would
fail to fail, which is probably why it went unnoticed for so long.

Patch submitted by Joel Jacobson after seeing an article by Andrey
Karpov in which he reports finding this through static code
analysis using PVS-Studio.  While I was at it I moved a definition
of a local variable referenced in the buggy code to a more local
context.

Backpatch to all supported branches.

diff --git a/src/backend/utils/adt/pgstatfuncs.c b/src/backend/utils/adt/pgstatfuncs.c
index 0533cd6b3eb396e3a01b2f48cc17e850fcc199ea..2957fc77dfcc0745ae4fdd7e4e3eac803d24fa0f 100644 (file)
--- a/src/backend/utils/adt/pgstatfuncs.c
+++ b/src/backend/utils/adt/pgstatfuncs.c
@@ -618,7 +618,6 @@ pg_stat_get_activity(PG_FUNCTION_ARGS)
                bool            nulls[14];
                HeapTuple       tuple;
                PgBackendStatus *beentry;
-               SockAddr        zero_clientaddr;
 
                MemSet(values, 0, sizeof(values));
                MemSet(nulls, 0, sizeof(nulls));
@@ -659,6 +658,8 @@ pg_stat_get_activity(PG_FUNCTION_ARGS)
                /* Values only available to same user or superuser */
                if (superuser() || beentry->st_userid == GetUserId())
                {
+                       SockAddr        zero_clientaddr;
+
                        switch (beentry->st_state)
                        {
                                case STATE_IDLE:
@@ -710,7 +711,7 @@ pg_stat_get_activity(PG_FUNCTION_ARGS)
                        /* A zeroed client addr means we don't know */
                        memset(&zero_clientaddr, 0, sizeof(zero_clientaddr));
                        if (memcmp(&(beentry->st_clientaddr), &zero_clientaddr,
-                                          sizeof(zero_clientaddr) == 0))
+                                          sizeof(zero_clientaddr)) == 0)
                        {
                                nulls[11] = true;
                                nulls[12] = true;
@@ -974,7 +975,7 @@ pg_stat_get_backend_client_addr(PG_FUNCTION_ARGS)
        /* A zeroed client addr means we don't know */
        memset(&zero_clientaddr, 0, sizeof(zero_clientaddr));
        if (memcmp(&(beentry->st_clientaddr), &zero_clientaddr,
-                          sizeof(zero_clientaddr) == 0))
+                          sizeof(zero_clientaddr)) == 0)
                PG_RETURN_NULL();
 
        switch (beentry->st_clientaddr.addr.ss_family)
@@ -1021,7 +1022,7 @@ pg_stat_get_backend_client_port(PG_FUNCTION_ARGS)
        /* A zeroed client addr means we don't know */
        memset(&zero_clientaddr, 0, sizeof(zero_clientaddr));
        if (memcmp(&(beentry->st_clientaddr), &zero_clientaddr,
-                          sizeof(zero_clientaddr) == 0))
+                          sizeof(zero_clientaddr)) == 0)
                PG_RETURN_NULL();
 
        switch (beentry->st_clientaddr.addr.ss_family)