Simplify tdeletechar and tinsertblank and fix memory corruption.

[st.git] / st.c

diff --git a/st.c b/st.c
index bb3e687..263abaa 100644 (file)
--- a/st.c
+++ b/st.c
@@ -549,12 +549,10 @@ xrealloc(void *p, size_t len) {
 
 char *
 xstrdup(char *s) {
-       char *p = strdup(s);
-
-       if (!p)
+       if((s = strdup(s)) == NULL)
                die("Out of memory\n");
 
-       return p;
+       return s;
 }
 
 size_t
@@ -1400,15 +1398,13 @@ tscrolldown(int orig, int n) {
 
        LIMIT(n, 0, term.bot-orig+1);
 
+       tsetdirt(orig, term.bot-n);
        tclearregion(0, term.bot-n+1, term.col-1, term.bot);
 
        for(i = term.bot; i >= orig+n; i--) {
                temp = term.line[i];
                term.line[i] = term.line[i-n];
                term.line[i-n] = temp;
-
-               term.dirty[i] = 1;
-               term.dirty[i-n] = 1;
        }
 
        selscroll(orig, n);
@@ -1418,17 +1414,16 @@ void
 tscrollup(int orig, int n) {
        int i;
        Line temp;
+
        LIMIT(n, 0, term.bot-orig+1);
 
        tclearregion(0, orig, term.col-1, orig+n-1);
+       tsetdirt(orig+n, term.bot);
 
        for(i = orig; i <= term.bot-n; i++) {
-                temp = term.line[i];
-                term.line[i] = term.line[i+n];
-                term.line[i+n] = temp;
-
-                term.dirty[i] = 1;
-                term.dirty[i+n] = 1;
+               temp = term.line[i];
+               term.line[i] = term.line[i+n];
+               term.line[i+n] = temp;
        }
 
        selscroll(orig, -n);
@@ -1591,37 +1586,31 @@ tclearregion(int x1, int y1, int x2, int y2) {
 
 void
 tdeletechar(int n) {
-       int src = term.c.x + n;
-       int dst = term.c.x;
-       int size = term.col - src;
+       int dst, src, size;
 
-       term.dirty[term.c.y] = 1;
+       LIMIT(n, 0, term.col - term.c.x);
 
-       if(src >= term.col) {
-               tclearregion(term.c.x, term.c.y, term.col-1, term.c.y);
-               return;
-       }
+       dst = term.c.x;
+       src = term.c.x + n;
+       size = term.col - src;
 
        memmove(&term.line[term.c.y][dst], &term.line[term.c.y][src],
-                       size * sizeof(Glyph));
+               size * sizeof(Glyph));
        tclearregion(term.col-n, term.c.y, term.col-1, term.c.y);
 }
 
 void
 tinsertblank(int n) {
-       int src = term.c.x;
-       int dst = src + n;
-       int size = term.col - dst;
+       int dst, src, size;
 
-       term.dirty[term.c.y] = 1;
+       LIMIT(n, 0, term.col - term.c.x);
 
-       if(dst >= term.col) {
-               tclearregion(term.c.x, term.c.y, term.col-1, term.c.y);
-               return;
-       }
+       dst = term.c.x + n;
+       src = term.c.x;
+       size = term.col - dst;
 
        memmove(&term.line[term.c.y][dst], &term.line[term.c.y][src],
-                       size * sizeof(Glyph));
+               size * sizeof(Glyph));
        tclearregion(src, term.c.y, dst - 1, term.c.y);
 }
 
@@ -2310,9 +2299,9 @@ techo(char *buf, int len) {
        for(; len > 0; buf++, len--) {
                char c = *buf;
 
-               if(c < '\x20') { /* control code */
+               if(c < 0x20 || c == 0177) { /* control code */
                        if(c != '\n' && c != '\r' && c != '\t') {
-                               c |= '\x40';
+                               c ^= '\x40';
                                tputc("^", 1);
                        }
                        tputc(&c, 1);