1 files changed, 26 insertions, 7 deletions

diff --git a/st.c b/st.c
index 4a77d71..657fba7 100644
--- a/st.c
+++ b/st.c
@@ -97,6 +97,7 @@ enum cursor_movement {
 enum cursor_state {
         CURSOR_DEFAULT  = 0,
         CURSOR_WRAPNEXT = 1,
+        CURSOR_ORIGIN   = 2
 };
 
 enum glyph_state {
@@ -300,6 +301,7 @@ static void tdeleteline(int);
 static void tinsertblank(int);
 static void tinsertblankline(int);
 static void tmoveto(int, int);
+static void tmoveato(int x, int y);
 static void tnew(int, int);
 static void tnewline(int);
 static void tputtab(bool);
@@ -1211,10 +1213,25 @@ csiparse(void) {
         }
 }
 
+/* for absolute user moves, when decom is set */
+void
+tmoveato(int x, int y) {
+        tmoveto(x, y + ((term.c.state & CURSOR_ORIGIN) ? term.top: 0));
+}
+
 void
 tmoveto(int x, int y) {
+        int miny, maxy;
+
+        if(term.c.state & CURSOR_ORIGIN) {
+                miny = term.top;
+                maxy = term.bot;
+        } else {
+                miny = 0;
+                maxy = term.row - 1;
+        }
         LIMIT(x, 0, term.col-1);
-        LIMIT(y, 0, term.row-1);
+        LIMIT(y, miny, maxy);
         term.c.state &= ~CURSOR_WRAPNEXT;
         term.c.x = x;
         term.c.y = y;
@@ -1456,7 +1473,9 @@ tsetmode(bool priv, bool set, int *args, int narg) {
                                 if(mode != term.mode)
                                         redraw();
                                 break;
-                        case 6: /* XXX: DECOM -- Origin */
+                        case 6: /* DECOM -- Origin */
+                                MODBIT(term.c.state, set, CURSOR_ORIGIN);
+                                tmoveato(0, 0);
                                 break;
                         case 7: /* DECAWM -- Auto wrap */
                                 MODBIT(term.mode, set, MODE_WRAP);
@@ -1593,7 +1612,7 @@ csihandle(void) {
         case 'f': /* HVP */
                 DEFAULT(csiescseq.arg[0], 1);
                 DEFAULT(csiescseq.arg[1], 1);
-                tmoveto(csiescseq.arg[1]-1, csiescseq.arg[0]-1);
+                tmoveato(csiescseq.arg[1]-1, csiescseq.arg[0]-1);
                 break;
         case 'I': /* CHT -- Cursor Forward Tabulation <n> tab stops */
                 DEFAULT(csiescseq.arg[0], 1);
@@ -1667,7 +1686,7 @@ csihandle(void) {
                 break;
         case 'd': /* VPA -- Move to <row> */
                 DEFAULT(csiescseq.arg[0], 1);
-                tmoveto(term.c.x, csiescseq.arg[0]-1);
+                tmoveato(term.c.x, csiescseq.arg[0]-1);
                 break;
         case 'h': /* SM -- Set terminal mode */
                 tsetmode(csiescseq.priv, 1, csiescseq.arg, csiescseq.narg);
@@ -1682,7 +1701,7 @@ csihandle(void) {
                         DEFAULT(csiescseq.arg[0], 1);
                         DEFAULT(csiescseq.arg[1], term.row);
                         tsetscroll(csiescseq.arg[0]-1, csiescseq.arg[1]-1);
-                        tmoveto(0, 0);
+                        tmoveato(0, 0);
                 }
                 break;
         case 's': /* DECSC -- Save cursor position (ANSI.SYS) */
@@ -2119,10 +2138,10 @@ tresize(int col, int row) {
         /* update terminal size */
         term.col = col;
         term.row = row;
-        /* make use of the LIMIT in tmoveto */
-        tmoveto(term.c.x, term.c.y);
         /* reset scrolling region */
         tsetscroll(0, row-1);
+        /* make use of the LIMIT in tmoveto */
+        tmoveto(term.c.x, term.c.y);
 
         return (slide > 0);
 }