[libgda] GdaHolder: fix memory leak at set value

[Daniel Espinosa Ortiz <despinosa src gnome org>]

commit edfa627502e546e5182a0fc4676dc488ff31cf2b
Author: Daniel Espinosa <esodan gmail com>
Date:   Mon Apr 22 15:07:03 2019 -0500

    GdaHolder: fix memory leak at set value
    
    Changed a warning to an error message.

 libgda/gda-holder.c | 32 +++++++++++++++++---------------
 libgda/gda-holder.h |  3 ++-
 2 files changed, 19 insertions(+), 16 deletions(-)
---
diff --git a/libgda/gda-holder.c b/libgda/gda-holder.c
index 39e63321a..7a11ea05c 100644
--- a/libgda/gda-holder.c
+++ b/libgda/gda-holder.c
@@ -997,19 +997,22 @@ real_gda_holder_set_value (GdaHolder *holder, GValue *value, gboolean do_copy, G
         */
        if (!priv->is_freeable) {
                gda_holder_unlock ((GdaLockable*) holder);
-               g_warning (_("Can't use this method to set value because there is already a static value"));
+               g_set_error (error, GDA_HOLDER_ERROR, GDA_HOLDER_VALUE_CHANGE_ERROR,
+                 (_("Can't use this method to set value because there is already a static value")));
                return FALSE;
        }
+       new_value = value;
        // If value's type is compatible to current holder's value's type transform it
        if (value && priv->g_type != G_VALUE_TYPE (value)
           && g_value_type_transformable (G_VALUE_TYPE (value), priv->g_type))
        {
                new_value = gda_value_new (priv->g_type);
                g_value_transform (value, new_value);
-               if (!do_copy && value)
-                       gda_value_free (value);
-       } else {
-               new_value = value;
+       }
+  else {
+    if (do_copy && value != NULL) {
+      new_value = gda_value_copy (value);
+    }
        }
        /* holder will be changed? */
        newnull = !new_value || GDA_VALUE_HOLDS_NULL (new_value);
@@ -1025,7 +1028,7 @@ real_gda_holder_set_value (GdaHolder *holder, GValue *value, gboolean do_copy, G
        /* holder's validity */
        newvalid = TRUE;
        if (newnull && priv->not_null) {
-               g_set_error (error, GDA_HOLDER_ERROR, GDA_HOLDER_VALUE_NULL_ERROR,
+         g_set_error (error, GDA_HOLDER_ERROR, GDA_HOLDER_VALUE_NULL_ERROR,
                             _("(%s): Holder does not allow NULL values"),
                             priv->id);
                newvalid = FALSE;
@@ -1056,7 +1059,7 @@ real_gda_holder_set_value (GdaHolder *holder, GValue *value, gboolean do_copy, G
 
        /* end of procedure if the value has not been changed, after calculating the holder's validity */
        if (!changed) {
-               if (!do_copy && new_value)
+               if (new_value)
                        gda_value_free (new_value);
                priv->invalid_forced = FALSE;
                if (priv->invalid_error) {
@@ -1079,7 +1082,7 @@ real_gda_holder_set_value (GdaHolder *holder, GValue *value, gboolean do_copy, G
                                 lerror->message);
 #endif
                        g_propagate_error (error, lerror);
-                       if (!do_copy) 
+                       if (new_value)
                                gda_value_free (new_value);
                        gda_holder_unlock ((GdaLockable*) holder);
                        return FALSE;
@@ -1113,7 +1116,10 @@ real_gda_holder_set_value (GdaHolder *holder, GValue *value, gboolean do_copy, G
                         holder, priv->full_bind, priv->full_bind);
 #endif
                gda_holder_unlock ((GdaLockable*) holder);
-               return real_gda_holder_set_value (priv->full_bind, new_value, do_copy, error);
+    gboolean ret = real_gda_holder_set_value (priv->full_bind, new_value, do_copy, error);
+    if (new_value)
+      gda_value_free (new_value);
+               return ret;
        }
        else {
                if (priv->value) {
@@ -1123,13 +1129,9 @@ real_gda_holder_set_value (GdaHolder *holder, GValue *value, gboolean do_copy, G
 
                if (new_value) {
                        if (newvalid) {
-                               if (do_copy)
-                                       priv->value = gda_value_copy (new_value);
-                               else
-                                       priv->value = new_value;
+                               priv->value = gda_value_copy (new_value);
                        }
-                       else if (!do_copy) 
-                               gda_value_free (new_value);
+                       gda_value_free (new_value);
                }
 
                gda_holder_unlock ((GdaLockable*) holder);
diff --git a/libgda/gda-holder.h b/libgda/gda-holder.h
index ff4ce3dc8..5da6fcfb1 100644
--- a/libgda/gda-holder.h
+++ b/libgda/gda-holder.h
@@ -35,7 +35,8 @@ extern GQuark gda_holder_error_quark (void);
 typedef enum {
        GDA_HOLDER_STRING_CONVERSION_ERROR,
        GDA_HOLDER_VALUE_TYPE_ERROR,
-       GDA_HOLDER_VALUE_NULL_ERROR
+       GDA_HOLDER_VALUE_NULL_ERROR,
+  GDA_HOLDER_VALUE_CHANGE_ERROR
 } GdaHolderError;
 
 #define GDA_TYPE_HOLDER          (gda_holder_get_type())