[libgda] Virtual provider: fixed reporting of errors while getting data

[Vivien Malerba <vivien src gnome org>]

commit 3491056aa302ede712d8da567ee26103c0f2ed68
Author: Vivien Malerba <malerba gnome-db org>
Date:   Mon Dec 1 20:42:56 2014 +0100

    Virtual provider: fixed reporting of errors while getting data

 libgda/gda-data-model-iter.c                     |   23 +++++++++++++++------
 libgda/sqlite/virtual/gda-vprovider-data-model.c |    7 +++++-
 2 files changed, 22 insertions(+), 8 deletions(-)
---
diff --git a/libgda/gda-data-model-iter.c b/libgda/gda-data-model-iter.c
index f2fd5a4..6ad4bca 100644
--- a/libgda/gda-data-model-iter.c
+++ b/libgda/gda-data-model-iter.c
@@ -1061,8 +1061,12 @@ gda_data_model_iter_get_value_at (GdaDataModelIter *iter, gint col)
        g_return_val_if_fail (iter->priv, NULL);
 
        param = (GdaHolder *) g_slist_nth_data (((GdaSet *) iter)->holders, col);
-       if (param)
-               return gda_holder_get_value (param);
+       if (param) {
+               if (gda_holder_is_valid (param))
+                       return gda_holder_get_value (param);
+               else
+                       return NULL;
+       }
        else
                return NULL;
 }
@@ -1089,9 +1093,10 @@ gda_data_model_iter_get_value_at_e (GdaDataModelIter *iter, gint col, GError **e
 
        param = (GdaHolder *) g_slist_nth_data (((GdaSet *) iter)->holders, col);
        if (param) {
-               if (error)
-                       gda_holder_is_valid_e (param, error);
-               return gda_holder_get_value (param);
+               if (gda_holder_is_valid_e (param, error))
+                       return gda_holder_get_value (param);
+               else
+                       return NULL;
        }
        else
                return NULL;
@@ -1145,8 +1150,12 @@ gda_data_model_iter_get_value_for_field (GdaDataModelIter *iter, const gchar *fi
        g_return_val_if_fail (iter->priv, NULL);
 
        param = gda_set_get_holder ((GdaSet *) iter, field_name);
-       if (param)
-               return gda_holder_get_value (param);
+       if (param) {
+               if (gda_holder_is_valid (param))
+                       return gda_holder_get_value (param);
+               else
+                       return NULL;
+       }
        else
                return NULL;
 }
diff --git a/libgda/sqlite/virtual/gda-vprovider-data-model.c 
b/libgda/sqlite/virtual/gda-vprovider-data-model.c
index 6207adf..0393eaf 100644
--- a/libgda/sqlite/virtual/gda-vprovider-data-model.c
+++ b/libgda/sqlite/virtual/gda-vprovider-data-model.c
@@ -1018,9 +1018,14 @@ virtualColumn (sqlite3_vtab_cursor *cur, sqlite3_context *ctx, int i)
        else if (G_VALUE_TYPE (value) == G_TYPE_ERROR) {
                GError *lerror;
                lerror = g_value_get_boxed (value);
-               //SQLITE3_CALL (sqlite3_result_error) (ctx, lerror && lerror->message ? lerror->message : 
_("No detail"), -1);
+               /* Can't call:
+                * SQLITE3_CALL (sqlite3_result_error) (ctx, lerror && lerror->message ? lerror->message : 
_("No detail"), -1);
+                * because then the whole processing stops and no further rows are read */
                if (lerror)
                        lerror = g_error_copy (lerror);
+               else
+                       g_set_error (&lerror, GDA_SERVER_PROVIDER_ERROR, GDA_SERVER_PROVIDER_DATA_ERROR,
+                                    _("No detail"));
                g_hash_table_insert (error_blobs_hash, lerror, GINT_TO_POINTER (1));
                SQLITE3_CALL (sqlite3_result_blob) (ctx, lerror, sizeof (GError), NULL);
        }