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 89fb28a402b88f438d84330e5f10b42f77f1870a..5d2e3b33db87039276d47d3fe9f8e69cd58b5ba2 100644 (file)
--- a/src/backend/utils/adt/pgstatfuncs.c
+++ b/src/backend/utils/adt/pgstatfuncs.c
@@ -482,7 +482,6 @@ pg_stat_get_activity(PG_FUNCTION_ARGS)
                bool            nulls[10];
                HeapTuple       tuple;
                PgBackendStatus *beentry;
-               SockAddr        zero_clientaddr;
 
                MemSet(values, 0, sizeof(values));
                MemSet(nulls, 0, sizeof(nulls));
@@ -515,6 +514,8 @@ pg_stat_get_activity(PG_FUNCTION_ARGS)
                /* Values only available to same user or superuser */
                if (superuser() || beentry->st_userid == GetUserId())
                {
+                       SockAddr        zero_clientaddr;
+
                        if (*(beentry->st_activity) == '\0')
                        {
                                values[3] = CStringGetTextDatum("<command string not enabled>");
@@ -544,7 +545,7 @@ 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[8] = true;
                                nulls[9] = true;
@@ -797,7 +798,7 @@ 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)
@@ -844,7 +845,7 @@ 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)