samterm: move cursor to next tabstop or non-space character before backspacing in...

diff --git a/sys/src/cmd/samterm/main.c b/sys/src/cmd/samterm/main.c
index 6ee72c94aa12295c23481766d0c121356bfd5244..c20091acb26db2dff922e765ee95873a07866965 100644 (file)
--- a/sys/src/cmd/samterm/main.c
+++ b/sys/src/cmd/samterm/main.c
@@ -359,19 +359,29 @@ getcol(Rasp *r, long p)
        return col;
 }
 
+int
+sptotab(Rasp *r, long p)
+{
+       int i, col, n;
+
+       col = getcol(r, p);
+       if((n = maxtab - col % maxtab) == maxtab)
+               n = 0;
+       for(i = 0; p < r->nrunes && raspc(r, p)==' ' && i<n; p++, i++)
+               ;
+       return i;
+}
+
 long
 del(Rasp *r, long o, long p)
 {
-       int i, col, n;
+       int i;
 
        if(--p < o)
                return o;
        if(!spacesindent || raspc(r, p)!=' ')
                return p;
-       col = getcol(r, p) + 1;
-       if((n = col % maxtab) == 0)
-               n = maxtab;
-       for(i = 0; p-1>=o && raspc(r, p-1)==' ' && i<n-1; --p, i++)
+       for(i = 0; p-1>=o && raspc(r, p-1)==' ' && i<maxtab-1; --p, i++)
                ;
        return p>=o? p : o;
 }
@@ -622,6 +632,8 @@ type(Flayer *l, int res)    /* what a bloody mess this is */
                        switch(c){
                        case '\b':
                        case 0x7F:      /* del */
+                               if(spacesindent)
+                                       a += sptotab(&t->rasp, a);
                                l->p0 = del(&t->rasp, l->origin, a);
                                break;
                        case 0x15:      /* ctrl-u */