Applying the CBT patch of Roberto Vargas. Thanks.

1 files changed, 36 insertions, 23 deletions

diff --git a/st.c b/st.c
index 5b98c6f..8cc0e1d 100644
--- a/st.c
+++ b/st.c
@@ -97,11 +97,11 @@ enum glyph_state {
 };
 
 enum term_mode {
-        MODE_WRAP        = 1,
+        MODE_WRAP       = 1,
         MODE_INSERT      = 2,
         MODE_APPKEYPAD   = 4,
         MODE_ALTSCREEN   = 8,
-        MODE_CRLF        = 16,
+        MODE_CRLF       = 16,
         MODE_MOUSEBTN    = 32,
         MODE_MOUSEMOTION = 64,
         MODE_MOUSE       = 32|64,
@@ -110,8 +110,8 @@ enum term_mode {
 
 enum escape_state {
         ESC_START      = 1,
-        ESC_CSI        = 2,
-        ESC_STR        = 4, /* DSC, OSC, PM, APC */
+        ESC_CSI = 2,
+        ESC_STR = 4, /* DSC, OSC, PM, APC */
         ESC_ALTCHARSET = 8,
         ESC_STR_END    = 16, /* a final string was encountered */
 };
@@ -152,21 +152,21 @@ typedef struct {
 /* ESC '[' [[ [<priv>] <arg> [;]] <mode>] */
 typedef struct {
         char buf[ESC_BUF_SIZ]; /* raw string */
-        int len;               /* raw string length */
+        int len;               /* raw string length */
         char priv;
         int arg[ESC_ARG_SIZ];
-        int narg;              /* nb of args */
+        int narg;             /* nb of args */
         char mode;
 } CSIEscape;
 
 /* STR Escape sequence structs */
 /* ESC type [[ [<priv>] <arg> [;]] <mode>] ESC '\' */
 typedef struct {
-        char type;             /* ESC type ... */
+        char type;           /* ESC type ... */
         char buf[STR_BUF_SIZ]; /* raw string */
-        int len;               /* raw string length */
+        int len;               /* raw string length */
         char *args[STR_ARG_SIZ];
-        int narg;              /* nb of args */
+        int narg;             /* nb of args */
 } STREscape;
 
 /* Internal representation of the screen */
@@ -262,7 +262,7 @@ static void tinsertblankline(int);
 static void tmoveto(int, int);
 static void tnew(int, int);
 static void tnewline(int);
-static void tputtab(void);
+static void tputtab(bool);
 static void tputc(char*);
 static void treset(void);
 static int tresize(int, int);
@@ -1243,7 +1243,7 @@ csihandle(void) {
         case 'I': /* CHT -- Cursor Forward Tabulation <n> tab stops */
                 DEFAULT(csiescseq.arg[0], 1);
                 while (csiescseq.arg[0]--)
-                        tputtab();
+                        tputtab(1);
                 break;
         case 'J': /* ED -- Clear screen */
                 sel.bx = -1;
@@ -1356,7 +1356,11 @@ csihandle(void) {
                 DEFAULT(csiescseq.arg[0], 1);
                 tdeletechar(csiescseq.arg[0]);
                 break;
-        /* XXX: (CSI n Z) CBT -- Cursor Backward Tabulation <n> tab stops */
+        case 'Z': /* CBT -- Cursor Backward Tabulation <n> tab stops */
+                DEFAULT(csiescseq.arg[0], 1);
+                while (csiescseq.arg[0]--)
+                        tputtab(0);
+                break;
         case 'd': /* VPA -- Move to <row> */
                 DEFAULT(csiescseq.arg[0], 1);
                 tmoveto(term.c.x, csiescseq.arg[0]-1);
@@ -1528,11 +1532,20 @@ strreset(void) {
 }
 
 void
-tputtab(void) {
-        unsigned x;
+tputtab(bool forward) {
+        unsigned x = term.c.x;
 
-        for (x = term.c.x + 1; x < term.col && !term.tabs[x]; ++x)
-                /* nothing */ ;
+        if (forward) {
+                if (x == term.col)
+                        return;
+                for (++x; x < term.col && !term.tabs[x]; ++x)
+                        /* nothing */ ;
+        } else {
+                if (x == 0)
+                        return;
+                for (--x; x > 0 && !term.tabs[x]; --x)
+                        /* nothing */ ;
+        }
         tmoveto(x, term.c.y);
 }
 
@@ -1650,7 +1663,7 @@ tputc(char *c) {
                         sel.bx = -1;
                 switch(ascii) {
                 case '\t':
-                        tputtab();
+                        tputtab(1);
                         break;
                 case '\b':
                         tmoveto(term.c.x-1, term.c.y);
@@ -1806,8 +1819,8 @@ void
 xclear(int x1, int y1, int x2, int y2) {
         XSetForeground(xw.dpy, dc.gc, dc.col[IS_SET(MODE_REVERSE) ? DefaultFG : DefaultBG]);
         XFillRectangle(xw.dpy, xw.buf, dc.gc,
-                       BORDER + x1 * xw.cw, BORDER + y1 * xw.ch,
-                       (x2-x1+1) * xw.cw, (y2-y1+1) * xw.ch);
+                       BORDER + x1 * xw.cw, BORDER + y1 * xw.ch,
+                       (x2-x1+1) * xw.cw, (y2-y1+1) * xw.ch);
 }
 
 void
@@ -1982,8 +1995,8 @@ xdraws(char *s, Glyph base, int x, int y, int charlen, int bytelen) {
 /* copy buffer pixmap to screen pixmap */
 void
 xcopy() {
-        XdbeSwapInfo swpinfo[1] = {{xw.win, XdbeCopied}};
-        XdbeSwapBuffers(xw.dpy, swpinfo, 1);
+        XdbeSwapInfo swpinfo[1] = {{xw.win, XdbeCopied}};
+        XdbeSwapBuffers(xw.dpy, swpinfo, 1);
 
 }
 
@@ -2080,8 +2093,8 @@ expose(XEvent *ev) {
         if(xw.state & WIN_REDRAW) {
                 if(!e->count)
                         xw.state &= ~WIN_REDRAW;
-        }
-        xcopy();
+        }
+        xcopy();
 }
 
 void