Fix pg_dump/pg_restore's ExecuteSqlCommand() to behave suitably if PQexec

returns NULL instead of a PGresult.  The former coding would fail, which
is OK, but it neglected to give you the PQerrorMessage that might tell
you why.  In the oldest branches, there was another problem: it'd sometimes
report PQerrorMessage from the wrong connection.

diff --git a/src/bin/pg_dump/pg_backup_db.c b/src/bin/pg_dump/pg_backup_db.c
index 947fa6ae60c20c9d8184f41b70317098731c5e3a..1bb33576bc850e27946a7b054baa143b148621c8 100644 (file)
--- a/src/bin/pg_dump/pg_backup_db.c
+++ b/src/bin/pg_dump/pg_backup_db.c
@@ -266,27 +266,31 @@ notice_processor(void *arg, const char *message)
 
 /* Public interface */
 /* Convenience function to send a query. Monitors result to handle COPY statements */
-static int
-ExecuteSqlCommand(ArchiveHandle *AH, PQExpBuffer qry, char *desc)
+static void
+ExecuteSqlCommand(ArchiveHandle *AH, const char *qry, const char *desc)
 {
        PGconn     *conn = AH->connection;
        PGresult   *res;
        char            errStmt[DB_MAX_ERR_STMT];
 
-       /* fprintf(stderr, "Executing: '%s'\n\n", qry->data); */
-       res = PQexec(conn, qry->data);
-       if (!res)
-               die_horribly(AH, modulename, "%s: no result from server\n", desc);
+#ifdef NOT_USED
+        fprintf(stderr, "Executing: '%s'\n\n", qry);
+#endif
+       res = PQexec(conn, qry);
 
-       if (PQresultStatus(res) != PGRES_COMMAND_OK && PQresultStatus(res) != PGRES_TUPLES_OK)
+       switch (PQresultStatus(res))
        {
-               if (PQresultStatus(res) == PGRES_COPY_IN)
-               {
+               case PGRES_COMMAND_OK:
+               case PGRES_TUPLES_OK:
+                       /* A-OK */
+                       break;
+               case PGRES_COPY_IN:
+                       /* Assume this is an expected result */
                        AH->pgCopyIn = true;
-               }
-               else
-               {
-                       strncpy(errStmt, qry->data, DB_MAX_ERR_STMT);
+                       break;
+               default:
+                       /* trouble */
+                       strncpy(errStmt, qry, DB_MAX_ERR_STMT);
                        if (errStmt[DB_MAX_ERR_STMT - 1] != '\0')
                        {
                                errStmt[DB_MAX_ERR_STMT - 4] = '.';
@@ -295,14 +299,11 @@ ExecuteSqlCommand(ArchiveHandle *AH, PQExpBuffer qry, char *desc)
                                errStmt[DB_MAX_ERR_STMT - 1] = '\0';
                        }
                        warn_or_die_horribly(AH, modulename, "%s: %s    Command was: %s\n",
-                                                                desc, PQerrorMessage(AH->connection),
-                                                                errStmt);
-               }
+                                                                desc, PQerrorMessage(conn), errStmt);
+                       break;
        }
 
        PQclear(res);
-
-       return strlen(qry->data);
 }
 
 /*
@@ -427,7 +428,7 @@ _sendSQLLine(ArchiveHandle *AH, char *qry, char *eos)
                                         * the buffer.
                                         */
                                        appendPQExpBufferChar(AH->sqlBuf, ';');         /* inessential */
-                                       ExecuteSqlCommand(AH, AH->sqlBuf,
+                                       ExecuteSqlCommand(AH, AH->sqlBuf->data,
                                                                          "could not execute query");
                                        resetPQExpBuffer(AH->sqlBuf);
                                        AH->sqlparse.lastChar = '\0';
@@ -626,25 +627,13 @@ ExecuteSqlCommandBuf(ArchiveHandle *AH, void *qryv, size_t bufLen)
 void
 StartTransaction(ArchiveHandle *AH)
 {
-       PQExpBuffer qry = createPQExpBuffer();
-
-       appendPQExpBuffer(qry, "BEGIN");
-
-       ExecuteSqlCommand(AH, qry, "could not start database transaction");
-
-       destroyPQExpBuffer(qry);
+       ExecuteSqlCommand(AH, "BEGIN", "could not start database transaction");
 }
 
 void
 CommitTransaction(ArchiveHandle *AH)
 {
-       PQExpBuffer qry = createPQExpBuffer();
-
-       appendPQExpBuffer(qry, "COMMIT");
-
-       ExecuteSqlCommand(AH, qry, "could not commit database transaction");
-
-       destroyPQExpBuffer(qry);
+       ExecuteSqlCommand(AH, "COMMIT", "could not commit database transaction");
 }
 
 static bool