[libgda] GdaDbCatalog: Fix memory leaks

[Daniel Espinosa Ortiz <despinosa src gnome org>]

commit 29b919ce004ee74082b4ccc7f55beae2c1b1bf25
Author: Daniel Espinosa <esodan gmail com>
Date:   Fri Apr 19 18:32:32 2019 -0500

    GdaDbCatalog: Fix memory leaks

 libgda/gda-db-catalog.c | 24 ++++++------------------
 1 file changed, 6 insertions(+), 18 deletions(-)
---
diff --git a/libgda/gda-db-catalog.c b/libgda/gda-db-catalog.c
index 38a3a033f..1e66bc8bd 100644
--- a/libgda/gda-db-catalog.c
+++ b/libgda/gda-db-catalog.c
@@ -212,10 +212,9 @@ _gda_db_catalog_get_dtd ()
   /* GdaDbCreator DTD */
        file = gda_gbr_get_file_path (GDA_DATA_DIR, LIBGDA_ABI_NAME, "dtd",
                                 "libgda-db-catalog.dtd", NULL);
-       if (g_file_test (file, G_FILE_TEST_EXISTS))
+       if (g_file_test (file, G_FILE_TEST_EXISTS)) {
                _gda_db_catalog_dtd = xmlParseDTD (NULL, (xmlChar*)file);
-  else
-    {
+  } else {
            if (g_getenv ("GDA_TOP_SRC_DIR"))
         {
           g_free (file);
@@ -225,12 +224,13 @@ _gda_db_catalog_get_dtd ()
                    }
          }
 
-  if (!_gda_db_catalog_dtd)
+  if (_gda_db_catalog_dtd != NULL) {
+    _gda_db_catalog_dtd->name = xmlStrdup((xmlChar*) "db-catalog");
+  } else {
          g_message (_("Could not parse '%s': "
                  "Validation for XML files for GdaDbCreator will not be performed (some weird errors may 
occur)"),
                file);
-  else
-               _gda_db_catalog_dtd->name = xmlStrdup((xmlChar*) "db-catalog");
+  }
 
        g_free (file);
   return _gda_db_catalog_dtd;
@@ -433,10 +433,6 @@ gda_db_catalog_parse_file_from_path (GdaDbCatalog *self,
   g_return_val_if_fail (self,FALSE);
   g_return_val_if_fail (xmlfile,FALSE);
 
-  xmlDtdPtr _gda_db_catalog_dtd = _gda_db_catalog_get_dtd ();
-
-  g_return_val_if_fail (_gda_db_catalog_dtd,FALSE);
-
   xmlDocPtr doc = NULL;
 
   doc = xmlParseFile (xmlfile);
@@ -488,10 +484,6 @@ gda_db_catalog_validate_file_from_path (const gchar *xmlfile,
 {
   g_return_val_if_fail (xmlfile, FALSE);
 
-  xmlDtdPtr _gda_db_catalog_dtd = _gda_db_catalog_get_dtd ();
-
-  g_return_val_if_fail (_gda_db_catalog_dtd, FALSE);
-
   xmlDocPtr doc = NULL;
 
   doc = xmlParseFile(xmlfile);
@@ -1034,10 +1026,6 @@ gda_db_catalog_parse_file (GdaDbCatalog *self,
   g_return_val_if_fail (self, FALSE);
   g_return_val_if_fail (xmlfile, FALSE);
 
-  xmlDtdPtr _gda_db_catalog_dtd = _gda_db_catalog_get_dtd ();
-
-  g_return_val_if_fail (_gda_db_catalog_dtd, FALSE);
-
   GFileInputStream *istream = NULL;
   xmlDocPtr doc = NULL;