Lookups: fix pgsql multiple-row, single-column return

Report & fix from James <list@xdrv.co.uk>; additional tidying and testcase by JGH

Broken-by: acec9514b1

1 files changed, 40 insertions, 46 deletions

diff --git a/src/src/lookups/pgsql.c b/src/src/lookups/pgsql.c
index 0b771f59c..cece43b66 100644
--- a/src/src/lookups/pgsql.c
+++ b/src/src/lookups/pgsql.c
@@ -140,7 +140,7 @@ has the password removed. This copy is also used for debugging output. */
 for (i = 2; i >= 0; i--)
   {
   uschar *pp = Ustrrchr(server, '/');
-  if (pp == NULL)
+  if (!pp)
     {
     *errmsg = string_sprintf("incomplete pgSQL server data: %s",
       (i == 2)? server : server_copy);
@@ -156,18 +156,16 @@ for (i = 2; i >= 0; i--)
 start is the identification of the server (host or path). See if we have a
 cached connection to the server. */
 
-for (cn = pgsql_connections; cn != NULL; cn = cn->next)
-  {
+for (cn = pgsql_connections; cn; cn = cn->next)
   if (Ustrcmp(cn->server, server_copy) == 0)
     {
     pg_conn = cn->handle;
     break;
     }
-  }
 
 /* If there is no cached connection, we must set one up. */
 
-if (cn == NULL)
+if (!cn)
   {
   uschar *port = US"";
 
@@ -178,7 +176,7 @@ if (cn == NULL)
     uschar *last_slash, *last_dot, *p;
 
     p = ++server;
-    while (*p != 0 && *p != ')') p++;
+    while (*p && *p != ')') p++;
     *p = 0;
 
     last_slash = Ustrrchr(server, '/');
@@ -191,10 +189,9 @@ if (cn == NULL)
     We have to call PQsetdbLogin with '/var/run/postgresql' as the hostname
     argument and put '5432' into the port variable. */
 
-    if (last_slash == NULL || last_dot == NULL)
+    if (!last_slash || !last_dot)
       {
-      *errmsg = string_sprintf("PGSQL invalid filename for socket: %s",
-        server);
+      *errmsg = string_sprintf("PGSQL invalid filename for socket: %s", server);
       *defer_break = TRUE;
       return DEFER;
       }
@@ -211,13 +208,13 @@ if (cn == NULL)
   else
     {
     uschar *p;
-    if ((p = Ustrchr(server, ':')) != NULL)
+    if ((p = Ustrchr(server, ':')))
       {
       *p++ = 0;
       port = p;
       }
 
-    if (Ustrchr(server, '/') != NULL)
+    if (Ustrchr(server, '/'))
       {
       *errmsg = string_sprintf("unexpected slash in pgSQL server hostname: %s",
         server);
@@ -280,37 +277,37 @@ else
 
 /* Run the query */
 
-  pg_result = PQexec(pg_conn, CS query);
-  switch(PQresultStatus(pg_result))
-    {
-    case PGRES_EMPTY_QUERY:
-    case PGRES_COMMAND_OK:
-      /* The command was successful but did not return any data since it was
-      not SELECT but either an INSERT, UPDATE or DELETE statement. Tell the
-      high level code to not cache this query, and clean the current cache for
-      this handle by setting *do_cache zero. */
-
-      result = string_cat(result, US PQcmdTuples(pg_result));
-      *do_cache = 0;
-      DEBUG(D_lookup) debug_printf("PGSQL: command does not return any data "
-	"but was successful. Rows affected: %s\n", result->s);
-      break;
+pg_result = PQexec(pg_conn, CS query);
+switch(PQresultStatus(pg_result))
+  {
+  case PGRES_EMPTY_QUERY:
+  case PGRES_COMMAND_OK:
+    /* The command was successful but did not return any data since it was
+    not SELECT but either an INSERT, UPDATE or DELETE statement. Tell the
+    high level code to not cache this query, and clean the current cache for
+    this handle by setting *do_cache zero. */
+
+    result = string_cat(result, US PQcmdTuples(pg_result));
+    *do_cache = 0;
+    DEBUG(D_lookup) debug_printf("PGSQL: command does not return any data "
+      "but was successful. Rows affected: %s\n", string_from_gstring(result));
+    break;
 
-    case PGRES_TUPLES_OK:
-      break;
+  case PGRES_TUPLES_OK:
+    break;
 
-    default:
-      /* This was the original code:
-      *errmsg = string_sprintf("PGSQL: query failed: %s\n",
-			       PQresultErrorMessage(pg_result));
-      This was suggested by a user:
-      */
-
-      *errmsg = string_sprintf("PGSQL: query failed: %s (%s) (%s)\n",
-                             PQresultErrorMessage(pg_result),
-                             PQresStatus(PQresultStatus(pg_result)), query);
-      goto PGSQL_EXIT;
-    }
+  default:
+    /* This was the original code:
+    *errmsg = string_sprintf("PGSQL: query failed: %s\n",
+			     PQresultErrorMessage(pg_result));
+    This was suggested by a user:
+    */
+
+    *errmsg = string_sprintf("PGSQL: query failed: %s (%s) (%s)\n",
+			   PQresultErrorMessage(pg_result),
+			   PQresStatus(PQresultStatus(pg_result)), query);
+    goto PGSQL_EXIT;
+  }
 
 /* Result is in pg_result. Find the number of fields returned. If this is one,
 we don't add field names to the data. Otherwise we do. If the query did not
@@ -329,7 +326,7 @@ for (i = 0; i < num_tuples; i++)
     result = string_catn(result, US"\n", 1);
 
   if (num_fields == 1)
-    result = string_catn(NULL,
+    result = string_catn(result,
 	US PQgetvalue(pg_result, i, 0), PQgetlength(pg_result, i, 0));
   else
     {
@@ -342,17 +339,13 @@ for (i = 0; i < num_tuples; i++)
     }
   }
 
-/* If result is NULL then no data has been found and so we return FAIL.
-Otherwise, we must terminate the string which has been built; string_cat()
-always leaves enough room for a terminating zero. */
+/* If result is NULL then no data has been found and so we return FAIL. */
 
 if (!result)
   {
   yield = FAIL;
   *errmsg = US"PGSQL: no data found";
   }
-else
-  store_reset(result->s + result->ptr + 1);
 
 /* Get here by goto from various error checks. */
 
@@ -367,6 +360,7 @@ if (pg_result) PQclear(pg_result);
 
 if (result)
   {
+  store_reset(result->s + result->ptr + 1);
   *resultptr = string_from_gstring(result);
   return OK;
   }