[libgda] postgres: adding error suppervision

[Daniel Espinosa Ortiz <despinosa src gnome org>]

commit b915953d6a2aa9b0a6e9bdffe6e5f7066b93036b
Author: Daniel Espinosa Ortiz <esodan gmail com>
Date:   Sun Feb 17 15:48:40 2019 -0600

    postgres: adding error suppervision

 libgda-ui/data-entries/gdaui-entry-shell.c           |  2 +-
 libgda/gda-data-select.c                             |  3 +++
 providers/postgres/gda-postgres-recordset.c          |  5 +++++
 .../reuseable/postgres/gda-postgres-reuseable.c      | 20 +++++++++++++++-----
 4 files changed, 24 insertions(+), 6 deletions(-)
---
diff --git a/libgda-ui/data-entries/gdaui-entry-shell.c b/libgda-ui/data-entries/gdaui-entry-shell.c
index 0efdc0300..704323ff3 100644
--- a/libgda-ui/data-entries/gdaui-entry-shell.c
+++ b/libgda-ui/data-entries/gdaui-entry-shell.c
@@ -96,7 +96,7 @@ typedef struct {
        GtkWidget           *stack;
        GtkWidget           *button; /* "..." button */
        GtkWidget           *label;
-        GdaDataHandler      *data_handler; /* FIXME: to remove if unused elsewhere */
+       GdaDataHandler      *data_handler; /* FIXME: to remove if unused elsewhere */
        gboolean             show_actions;
        gboolean             is_cell_renderer;
        gboolean             editable;
diff --git a/libgda/gda-data-select.c b/libgda/gda-data-select.c
index 2c0122f52..84408124c 100644
--- a/libgda/gda-data-select.c
+++ b/libgda/gda-data-select.c
@@ -1914,6 +1914,9 @@ static void dump_d (GdaDataSelect *model)
 static const GValue *
 gda_data_select_get_value_at (GdaDataModel *model, gint col, gint row, GError **error)
 {
+       g_return_val_if_fail (model != NULL, NULL);
+       g_return_val_if_fail (GDA_IS_DATA_SELECT (model), NULL);
+
        GdaRow *prow;
        gint int_row;
        GdaDataSelectPrivate *priv = gda_data_select_get_instance_private (GDA_DATA_SELECT (model));
diff --git a/providers/postgres/gda-postgres-recordset.c b/providers/postgres/gda-postgres-recordset.c
index 6d6c63116..9030f49bb 100644
--- a/providers/postgres/gda-postgres-recordset.c
+++ b/providers/postgres/gda-postgres-recordset.c
@@ -440,6 +440,9 @@ gda_postgres_recordset_fetch_nb_rows (GdaDataSelect *model)
 static gboolean
 gda_postgres_recordset_fetch_random (GdaDataSelect *model, GdaRow **prow, gint rownum, GError **error)
 {
+       g_return_val_if_fail (model != NULL, FALSE);
+       g_return_val_if_fail (GDA_IS_DATA_SELECT (model), FALSE);
+
        GdaPostgresRecordset *imodel = (GdaPostgresRecordset *) model;
 
        if (!imodel->priv->pg_res) {
@@ -819,6 +822,8 @@ set_prow_with_pg_res (GdaPostgresRecordset *imodel, GdaRow *prow, gint pg_res_ro
 static GdaRow *
 new_row_from_pg_res (GdaPostgresRecordset *imodel, gint pg_res_rownum, GError **error)
 {
+       g_return_val_if_fail (imodel != NULL, NULL);
+       g_return_val_if_fail (GDA_IS_DATA_SELECT (imodel), NULL);
        GdaRow *prow;
 
        prow = gda_row_new (_gda_data_select_get_prep_stmt ((GdaDataSelect*) imodel)->ncols);
diff --git a/providers/reuseable/postgres/gda-postgres-reuseable.c 
b/providers/reuseable/postgres/gda-postgres-reuseable.c
index c6c1e5c51..e0e358d43 100644
--- a/providers/reuseable/postgres/gda-postgres-reuseable.c
+++ b/providers/reuseable/postgres/gda-postgres-reuseable.c
@@ -185,11 +185,14 @@ _gda_postgres_compute_version (GdaConnection *cnc, GdaPostgresReuseable *rdata,
                return FALSE;
        
        const GValue *cvalue;
-       cvalue = gda_data_model_get_value_at (model, 0, 0, NULL);
+       GError *lerror = NULL;
+       cvalue = gda_data_model_get_value_at (model, 0, 0, &lerror);
        if (!cvalue) {
                g_set_error (error, GDA_SERVER_PROVIDER_ERROR,
-                             GDA_SERVER_PROVIDER_INTERNAL_ERROR, "%s",
-                             _("Can't get version data from server"));
+                           GDA_SERVER_PROVIDER_INTERNAL_ERROR,
+                           _("Can't get version data from server: %s"),
+                           lerror && lerror->message ? lerror->message : _("No detail"));
+               g_clear_error (&lerror);
                g_object_unref (model);
                return FALSE;
        }
@@ -305,8 +308,15 @@ _gda_postgres_compute_types (GdaConnection *cnc, GdaPostgresReuseable *rdata)
        gchar *avoid_types = NULL;
        GString *string;
 
-       if (rdata->version_float == 0)
-               _gda_postgres_compute_version (cnc, rdata, NULL);
+       if (rdata->version_float == 0) {
+               GError *lerror = NULL;
+               _gda_postgres_compute_version (cnc, rdata, &lerror);
+               if (lerror != NULL) {
+                       g_warning (_("Internal Error: Can't calculate PostgreSQL version: %s"),
+                                  lerror && lerror->message ? lerror->message : _("No detail"));
+                       return;
+               }
+       }
        if (rdata->version_float < 7.3) {
                gchar *query;
                avoid_types = "'SET', 'cid', 'oid', 'int2vector', 'oidvector', 'regproc', 'smgr', 'tid', 
'unknown', 'xid'";