[ghex] Fix revert for mmapBuf; other UI tweaks.

[Logan Rathbone <larathbone src gnome org>]

commit abbf1773ef906040221c6aa2f20d93bf00cd3749
Author: Logan Rathbone <poprocks gmail com>
Date:   Mon Dec 20 16:54:02 2021 -0500

    Fix revert for mmapBuf; other UI tweaks.

 src/ghex-application-window.c | 14 +++++++-------
 src/gtkhex.c                  |  3 +--
 src/hex-buffer-mmap.c         | 15 +++++++++++++++
 src/hex-document.c            |  1 -
 4 files changed, 23 insertions(+), 10 deletions(-)
---
diff --git a/src/ghex-application-window.c b/src/ghex-application-window.c
index c8ca6b6..09edbab 100644
--- a/src/ghex-application-window.c
+++ b/src/ghex-application-window.c
@@ -146,11 +146,14 @@ static void ghex_application_window_remove_tab (GHexApplicationWindow *self,
                GHexNotebookTab *tab);
 static GHexNotebookTab * ghex_application_window_get_current_tab (GHexApplicationWindow *self);
 
-static void set_statusbar(GHexApplicationWindow *self, const char *str);
+static void set_statusbar (GHexApplicationWindow *self, const char *str);
 static void update_status_message (GHexApplicationWindow *self);
 static void update_gui_data (GHexApplicationWindow *self);
 static gboolean assess_can_save (HexDocument *doc);
 
+static void doc_read_ready_cb (GObject *source_object, GAsyncResult *res,
+               gpointer user_data);
+
 /* GHexApplicationWindow -- PRIVATE FUNCTIONS */
 
 /* Common macro to apply something to the 'gh' of each tab of the notebook.
@@ -1135,10 +1138,9 @@ revert_response_cb (GtkDialog *dialog,
 
        doc = gtk_hex_get_document (ACTIVE_GH);
 
+       extra_user_data = ACTIVE_GH;
        show_doc_loading_spinner (self);
-
-       /* FIXME - error handling */
-       hex_document_read_async (doc, NULL, NULL, NULL);
+       hex_document_read_async (doc, NULL, doc_read_ready_cb, self);
 
 end:
        gtk_window_destroy (GTK_WINDOW(dialog));
@@ -2045,7 +2047,7 @@ do_nag_screen (GHexApplicationWindow *self)
 }
 #endif
 
-
+/* also takes extra_user_data ! Hooray for cheap shortcuts! */
 static void
 doc_read_ready_cb (GObject *source_object,
                GAsyncResult *res,
@@ -2086,8 +2088,6 @@ doc_read_ready_cb (GObject *source_object,
        extra_user_data = NULL;
 }
                        
-
-
 void
 ghex_application_window_open_file (GHexApplicationWindow *self, GFile *file)
 {
diff --git a/src/gtkhex.c b/src/gtkhex.c
index 53bae30..d3e6f61 100644
--- a/src/gtkhex.c
+++ b/src/gtkhex.c
@@ -2328,8 +2328,7 @@ gtk_hex_dispose (GObject *object)
        g_clear_object (&gh->alayout);
        g_clear_object (&gh->olayout);
 
-       g_object_unref (gh->document);
-//     g_clear_object (&gh->document);
+       g_clear_object (&gh->document);
        
        /* Chain up */
        G_OBJECT_CLASS(gtk_hex_parent_class)->dispose(object);
diff --git a/src/hex-buffer-mmap.c b/src/hex-buffer-mmap.c
index d813bc1..f3dc99f 100644
--- a/src/hex-buffer-mmap.c
+++ b/src/hex-buffer-mmap.c
@@ -521,6 +521,20 @@ create_fd_from_path (HexBufferMmap *self, const char *path)
        return fd;
 }
 
+static void
+clear_buffer (HexBufferMmap *self)
+{
+       if (self->fd)
+       {
+               close (self->fd);
+               clear_tmpfile_path (self);
+       }
+       if (self->data)
+               munmap (self->data, self->mapped);
+
+       self->payload = self->mapped = self->gap = 0;
+}
+
 static gboolean
 create_buffer (HexBufferMmap *self)
 {
@@ -592,6 +606,7 @@ hex_buffer_mmap_read (HexBuffer *buf)
        self->clean = p;
 
        /* Create dirty buffer for writing etc. */
+       clear_buffer (self);
        create_buffer (self);
 
        /* FIXME/TODO - sanity check against # of bytes read? */
diff --git a/src/hex-document.c b/src/hex-document.c
index 31a9f8e..24c9885 100644
--- a/src/hex-document.c
+++ b/src/hex-document.c
@@ -474,7 +474,6 @@ hex_document_read_finish (HexDocument *doc,
   return g_task_propagate_boolean (G_TASK (result), error);
 }
 
-
 static void
 document_ready_cb (GObject *source_object,
                GAsyncResult *res,