From 3a50c9572d90d553333d050e0c0af5be248e3bb8 Mon Sep 17 00:00:00 2001
From: Michael Jumper <mike.jumper@guac-dev.org>
Date: Fri, 26 Apr 2013 14:52:51 -0700
Subject: [PATCH] Clear cells when resizing or scrolling.

---
 protocols/ssh/src/display.c  | 34 +++++++++++++++++++++++++++-------
 protocols/ssh/src/terminal.c | 27 +++++++++++++++++++++++----
 2 files changed, 50 insertions(+), 11 deletions(-)

diff --git a/protocols/ssh/src/display.c b/protocols/ssh/src/display.c
index 40fde422..ede7f16e 100644
--- a/protocols/ssh/src/display.c
+++ b/protocols/ssh/src/display.c
@@ -410,9 +410,14 @@ void guac_terminal_display_resize(guac_terminal_display* display, int width, int
     guac_terminal_operation* current;
     int x, y;
 
-    /* Set width and height */
-    display->width = width;
-    display->height = height;
+    /* Fill with background color (index 0) */
+    guac_terminal_char fill = {
+        .value = ' ',
+        .attributes = {
+            .foreground = 0,
+            .background = 0
+        }
+    };
 
     /* Free old operations buffer */
     if (display->operations != NULL)
@@ -427,19 +432,34 @@ void guac_terminal_display_resize(guac_terminal_display* display, int width, int
     for (y=0; y<height; y++) {
 
         /* Init entire row to NOP */
-        for (x=0; x<width; x++)
-            (current++)->type = GUAC_CHAR_NOP;
+        for (x=0; x<width; x++) {
+
+            /* If on old part of screen, do not clear */
+            if (x < display->width && y < display->height)
+                current->type = GUAC_CHAR_NOP;
+
+            /* Otherwise, clear contents first */
+            else {
+                current->type = GUAC_CHAR_SET;
+                current->character  = fill;
+            }
+
+            current++;
+
+        }
 
     }
 
+    /* Set width and height */
+    display->width = width;
+    display->height = height;
+
     /* Send initial display size */
     guac_protocol_send_size(display->client->socket,
             GUAC_DEFAULT_LAYER,
             display->char_width  * width,
             display->char_height * height);
 
-
-
 }
 
 void __guac_terminal_display_flush_copy(guac_terminal_display* display) {
diff --git a/protocols/ssh/src/terminal.c b/protocols/ssh/src/terminal.c
index 54f26cdb..8419b63e 100644
--- a/protocols/ssh/src/terminal.c
+++ b/protocols/ssh/src/terminal.c
@@ -162,8 +162,21 @@ int guac_terminal_write(guac_terminal* term, const char* c, int size) {
 int guac_terminal_scroll_up(guac_terminal* term,
         int start_row, int end_row, int amount) {
 
-    /* Copy row data upwards */
-    guac_terminal_copy_rows(term, start_row + amount, end_row, -amount);
+    /* If scrolling entire display, update scroll offset */
+    if (start_row == 0 && end_row == term->term_height - 1) {
+
+        /* Scroll up visibly */
+        guac_terminal_display_copy_rows(term->display, start_row + amount, end_row, -amount);
+
+        /* Advance by scroll amount */
+        term->buffer->top += amount;
+        term->buffer->length += amount;
+
+    }
+
+    /* Otherwise, just copy row data upwards */
+    else
+        guac_terminal_copy_rows(term, start_row + amount, end_row, -amount);
 
     /* Clear new area */
     guac_terminal_clear_range(term,
@@ -274,8 +287,11 @@ void guac_terminal_scroll_display_down(guac_terminal* terminal,
         guac_terminal_buffer_row* buffer_row =
             guac_terminal_buffer_get_row(terminal->buffer, row, 0);
 
+        /* Clear row */
+        guac_terminal_display_set_columns(terminal->display,
+                dest_row, 0, terminal->display->width, &(terminal->default_char));
+
         /* Draw row */
-        /* FIXME: Clear row first */
         guac_terminal_char* current = buffer_row->characters;
         for (column=0; column<buffer_row->length; column++)
             guac_terminal_display_set_columns(terminal->display,
@@ -329,8 +345,11 @@ void guac_terminal_scroll_display_up(guac_terminal* terminal,
         guac_terminal_buffer_row* buffer_row = 
             guac_terminal_buffer_get_row(terminal->buffer, row, 0);
 
+        /* Clear row */
+        guac_terminal_display_set_columns(terminal->display,
+                dest_row, 0, terminal->display->width, &(terminal->default_char));
+
         /* Draw row */
-        /* FIXME: Clear row first */
         guac_terminal_char* current = buffer_row->characters;
         for (column=0; column<buffer_row->length; column++)
             guac_terminal_display_set_columns(terminal->display,