Fix/mute issues found by Coverity scan

This makes the code free of Coverity scan issues.
It is sometimes quite pedantic and expects/suggests some
coding habits, thus certain changes may look weird, but for a good
thing, I hope. The code is also tagged with Coverity scan
suppressions, to keep the code as is and hide the warning too.
Also note that Coverity treats g_return_if_fail(), g_assert() and
similar macros as unreliable, and it's true these can be disabled
during the compile time, thus it brings in other set of 'weird'
changes.

9 files changed, 56 insertions, 57 deletions

diff --git a/plugins/attachment-reminder/attachment-reminder.c b/plugins/attachment-reminder/attachment-reminder.c
index 52a03231b7..5ee371987e 100644
--- a/plugins/attachment-reminder/attachment-reminder.c
+++ b/plugins/attachment-reminder/attachment-reminder.c
@@ -622,9 +622,7 @@ e_plugin_lib_get_configure_widget (EPlugin *plugin)
 		gtk_list_store_set (ui->store, &iter, CLUE_KEYWORD_COLUMN, clue_list[i], -1);
 	}
 
-	if (clue_list) {
-		g_strfreev (clue_list);
-	}
+	g_strfreev (clue_list);
 
 	/* Add the list here */
 
diff --git a/plugins/dbx-import/dbx-importer.c b/plugins/dbx-import/dbx-importer.c
index 47a2bb94bf..5fe0863c31 100644
--- a/plugins/dbx-import/dbx-importer.c
+++ b/plugins/dbx-import/dbx-importer.c
@@ -446,7 +446,8 @@ dbx_read_mail_body (DbxImporter *m,
 	guint32 buflen = 0x200;
 	guchar *buffer = g_malloc (buflen);
 
-	ftruncate (bodyfd, 0);
+	if (ftruncate (bodyfd, 0) == -1)
+		g_warning ("%s: Failed to truncate file: %s", G_STRFUNC, g_strerror (errno));
 	lseek (bodyfd, 0, SEEK_SET);
 
 	while (offset) {
diff --git a/plugins/email-custom-header/email-custom-header.c b/plugins/email-custom-header/email-custom-header.c
index 78364fa84f..c7e8f50b45 100644
--- a/plugins/email-custom-header/email-custom-header.c
+++ b/plugins/email-custom-header/email-custom-header.c
@@ -177,6 +177,7 @@ epech_header_options_cb (GtkDialog *dialog,
 	switch (state) {
 		case GTK_RESPONSE_OK:
 			epech_get_widgets_data (mch);
+			/* coverity[fallthrough] */
 		case GTK_RESPONSE_CANCEL:
 			gtk_widget_hide (priv->main);
 			gtk_widget_destroy (priv->main);
diff --git a/plugins/external-editor/external-editor.c b/plugins/external-editor/external-editor.c
index 8f6e782919..97cb6abf5e 100644
--- a/plugins/external-editor/external-editor.c
+++ b/plugins/external-editor/external-editor.c
@@ -26,6 +26,8 @@
 #include <config.h>
 #endif
 
+#include <errno.h>
+
 #include <mail/em-config.h>
 #include <mail/em-composer-utils.h>
 #include <e-msg-composer.h>
@@ -374,7 +376,9 @@ external_editor_thread (gpointer user_data)
 			g_idle_add ((GSourceFunc) update_composer_text, array);
 
 			/* We no longer need that temporary file */
-			g_remove (filename);
+			if (g_remove (filename) == -1)
+				g_warning ("%s: Failed to remove file '%s': %s",
+					   G_STRFUNC, filename, g_strerror (errno));
 			g_free (filename);
 		}
 	}
diff --git a/plugins/mail-to-task/mail-to-task.c b/plugins/mail-to-task/mail-to-task.c
index b2c995e0e8..f4bfe1927a 100644
--- a/plugins/mail-to-task/mail-to-task.c
+++ b/plugins/mail-to-task/mail-to-task.c
@@ -852,23 +852,19 @@ do_mail_to_event (AsyncData *data)
 	if (error != NULL) {
 		report_error_idle (_("Cannot open calendar. %s"), error->message);
 	} else if (e_client_is_readonly (E_CLIENT (client))) {
-		if (error != NULL)
-			report_error_idle ("Check readonly failed. %s", error->message);
-		else {
-			switch (data->source_type) {
-			case E_CAL_CLIENT_SOURCE_TYPE_EVENTS:
-				report_error_idle (_("Selected calendar is read only, thus cannot create event there. Select other calendar, please."), NULL);
-				break;
-			case E_CAL_CLIENT_SOURCE_TYPE_TASKS:
-				report_error_idle (_("Selected task list is read only, thus cannot create task there. Select other task list, please."), NULL);
-				break;
-			case E_CAL_CLIENT_SOURCE_TYPE_MEMOS:
-				report_error_idle (_("Selected memo list is read only, thus cannot create memo there. Select other memo list, please."), NULL);
-				break;
-			default:
-				g_assert_not_reached ();
-				break;
-			}
+		switch (data->source_type) {
+		case E_CAL_CLIENT_SOURCE_TYPE_EVENTS:
+			report_error_idle (_("Selected calendar is read only, thus cannot create event there. Select other calendar, please."), NULL);
+			break;
+		case E_CAL_CLIENT_SOURCE_TYPE_TASKS:
+			report_error_idle (_("Selected task list is read only, thus cannot create task there. Select other task list, please."), NULL);
+			break;
+		case E_CAL_CLIENT_SOURCE_TYPE_MEMOS:
+			report_error_idle (_("Selected memo list is read only, thus cannot create memo there. Select other memo list, please."), NULL);
+			break;
+		default:
+			g_assert_not_reached ();
+			break;
 		}
 	} else {
 		gint i;
@@ -1114,7 +1110,6 @@ mail_to_event (ECalClientSourceType source_type,
 	GList *list, *iter;
 	GtkWindow *parent;
 	const gchar *extension_name;
-	GError *error = NULL;
 
 	parent = e_mail_reader_get_window (reader);
 	uids = e_mail_reader_get_selected_uids (reader);
@@ -1193,16 +1188,6 @@ mail_to_event (ECalClientSourceType source_type,
 				E_SOURCE_SELECTOR_DIALOG (dialog));
 
 		gtk_widget_destroy (dialog);
-	} else if (!source && default_source) {
-		source = default_source;
-	} else if (!source) {
-		e_notice (
-			NULL, GTK_MESSAGE_ERROR,
-			_("No writable calendar is available."));
-
-		if (error != NULL)
-			g_error_free (error);
-		goto exit;
 	}
 
 	if (source) {
@@ -1234,7 +1219,6 @@ mail_to_event (ECalClientSourceType source_type,
 		}
 	}
 
-exit:
 	g_object_unref (default_source);
 	g_ptr_array_unref (uids);
 }
diff --git a/plugins/mailing-list-actions/mailing-list-actions.c b/plugins/mailing-list-actions/mailing-list-actions.c
index d9466013c2..35a379c771 100644
--- a/plugins/mailing-list-actions/mailing-list-actions.c
+++ b/plugins/mailing-list-actions/mailing-list-actions.c
@@ -229,7 +229,7 @@ emla_list_action_cb (CamelFolder *folder,
 		/* get URL portion */
 		url = g_strndup (headerpos, end - headerpos);
 
-		if (strncmp (url, "mailto:", 6) == 0) {
+		if (url && strncmp (url, "mailto:", 6) == 0) {
 			if (emla_action_headers[t].interactive)
 				send_message_response = GTK_RESPONSE_NO;
 			else
@@ -253,7 +253,7 @@ emla_list_action_cb (CamelFolder *folder,
 			}
 
 			goto exit;
-		} else {
+		} else if (url && *url) {
 			e_show_uri (window, url);
 			goto exit;
 		}
diff --git a/plugins/pst-import/pst-importer.c b/plugins/pst-import/pst-importer.c
index 853a16cbd8..f16f476920 100644
--- a/plugins/pst-import/pst-importer.c
+++ b/plugins/pst-import/pst-importer.c
@@ -807,13 +807,14 @@ pst_import_folders (PstImporter *m,
                     pst_desc_tree *topitem)
 {
 	GHashTable *node_to_folderuri; /* pointers of hierarchy nodes, to them associated folder uris */
-	pst_desc_tree *d_ptr;
+	pst_desc_tree *d_ptr = NULL;
 
 	node_to_folderuri = g_hash_table_new_full (g_direct_hash, g_direct_equal, NULL, g_free);
-	d_ptr = topitem->child;
 
-	if (topitem)
+	if (topitem) {
+		d_ptr = topitem->child;
 		g_hash_table_insert (node_to_folderuri, topitem, g_strdup (m->folder_uri));
+	}
 
 	/* Walk through folder tree */
 	while (d_ptr != NULL && (g_cancellable_is_cancelled (m->cancellable) == FALSE)) {
@@ -866,7 +867,7 @@ pst_import_folders (PstImporter *m,
 				break;
 			}
 
-			d_ptr = d_ptr->next;
+			d_ptr = d_ptr ? d_ptr->next : NULL;
 		}
 
 		g_free (previous_folder);
@@ -1865,6 +1866,8 @@ fill_calcomponent (PstImporter *m,
 		case PST_FREEBUSY_FREE:
 			/* mark as transparent and as confirmed */
 			e_cal_component_set_transparency (ec, E_CAL_COMPONENT_TRANSP_TRANSPARENT);
+			e_cal_component_set_status (ec, ICAL_STATUS_CONFIRMED);
+			break;
 		case PST_FREEBUSY_BUSY:
 		case PST_FREEBUSY_OUT_OF_OFFICE:
 			e_cal_component_set_status (ec, ICAL_STATUS_CONFIRMED);
diff --git a/plugins/publish-calendar/url-editor-dialog.c b/plugins/publish-calendar/url-editor-dialog.c
index 04bbe5d9f9..d01c585307 100644
--- a/plugins/publish-calendar/url-editor-dialog.c
+++ b/plugins/publish-calendar/url-editor-dialog.c
@@ -72,6 +72,9 @@ create_uri (UrlEditorDialog *dialog)
 		case TYPE_ANON_FTP:
 			g_free (username);
 			username = g_strdup ("anonymous");
+			method = "ftp";
+			break;
+
 		case TYPE_FTP:
 			method = "ftp";
 			break;
diff --git a/plugins/save-calendar/save-calendar.c b/plugins/save-calendar/save-calendar.c
index c713612db8..e4228cb339 100644
--- a/plugins/save-calendar/save-calendar.c
+++ b/plugins/save-calendar/save-calendar.c
@@ -82,14 +82,14 @@ on_type_combobox_changed (GtkComboBox *combobox,
 		extra_widget_foreach_hide,
 		g_object_get_data (G_OBJECT (combobox), "format-box"));
 
-	gtk_combo_box_get_active_iter (combobox, &iter);
+	if (!gtk_combo_box_get_active_iter (combobox, &iter))
+		return;
 
 	gtk_tree_model_get (
 		model, &iter,
 		DEST_HANDLER, &handler, -1);
 
-	if (handler->options_widget)
-	{
+	if (handler && handler->options_widget) {
 		gtk_widget_show (handler->options_widget);
 	}
 
@@ -202,25 +202,30 @@ ask_destination_and_save (ESourceSelector *selector,
 	if (gtk_dialog_run (GTK_DIALOG (dialog)) == GTK_RESPONSE_OK) {
 		gchar *tmp = NULL;
 
-		gtk_combo_box_get_active_iter (combo, &iter);
-		gtk_tree_model_get (
-			model, &iter,
-			DEST_HANDLER, &handler, -1);
+		if (gtk_combo_box_get_active_iter (combo, &iter))
+			gtk_tree_model_get (
+				model, &iter,
+				DEST_HANDLER, &handler, -1);
+		else
+			handler = NULL;
 
-	       dest_uri = gtk_file_chooser_get_uri
-			(GTK_FILE_CHOOSER (dialog));
+		dest_uri = gtk_file_chooser_get_uri (GTK_FILE_CHOOSER (dialog));
 
-		tmp = strstr (dest_uri, handler->filename_ext);
+		if (handler) {
+			tmp = strstr (dest_uri, handler->filename_ext);
 
-		if (!(tmp && *(tmp + strlen (handler->filename_ext)) == '\0')) {
+			if (!(tmp && *(tmp + strlen (handler->filename_ext)) == '\0')) {
 
-			gchar *temp;
-			temp = g_strconcat (dest_uri, handler->filename_ext, NULL);
-			g_free (dest_uri);
-			dest_uri = temp;
-		}
+				gchar *temp;
+				temp = g_strconcat (dest_uri, handler->filename_ext, NULL);
+				g_free (dest_uri);
+				dest_uri = temp;
+			}
 
-		handler->save (handler, selector, type, dest_uri);
+			handler->save (handler, selector, type, dest_uri);
+		} else {
+			g_warn_if_reached ();
+		}
 	}
 
 	/* Free the handlers */