mirrors/janet
1
0
Fork 0
mirror of https://github.com/janet-lang/janet synced 2026-09-14 13:21:21 +00:00
Code Issues 1 Releases Wiki Activity

Fix #1723 - handle prompt longer than terminal is wide.

Browse Source 
When this happened, we tried to print a buffer with a negative length
that resulted in invalid memmove call. This fix both checks that we
don't tried to append a negative buffer, and truncates a prompt that is
too long for the termimal so that one can still enter text with at least
16 visible characters for data entry.
This commit is contained in:
Calvin Rose
2026-03-07 15:28:59 -06:00
parent decd7078af
commit 8f446736ed
1 changed files with 28 additions and 8 deletions
Download Patch File Download Diff File Expand all files Collapse all files
src/mainclient/shell.c
+28 -8
View File
@@ -26,6 +26,7 @@
#include <janet.h>
#include <errno.h>
#include <assert.h>
#ifdef _WIN32
#include <windows.h>
@@ -362,33 +363,50 @@ static void clear(void) {
}
}
static int getplen(void) {
int _plen = gbl_plen;
/* Ensure at least 16 characters of data entry; */
while (_plen && (_plen + 16 > gbl_cols)) {
_plen--;
}
return _plen;
}
static void refresh(void) {
char seq[64];
JanetBuffer b;
/* If prompt is too long, truncate */
int _plen = getplen();
/* Keep cursor position on screen */
char *_buf = gbl_buf;
int _len = gbl_len;
int _pos = gbl_pos;
while ((gbl_plen + _pos) >= gbl_cols) {
while ((_plen + _pos) >= gbl_cols) {
_buf++;
_len--;
_pos--;
}
while ((gbl_plen + _len) > gbl_cols) {
while ((_plen + _len) > gbl_cols) {
_len--;
}
janet_buffer_init(&b, 0);
/* Cursor to left edge, gbl_prompt and buffer */
janet_buffer_push_u8(&b, '\r');
janet_buffer_push_cstring(&b, gbl_prompt);
janet_buffer_push_bytes(&b, (uint8_t *) _buf, _len);
janet_buffer_push_bytes(&b, (const uint8_t *) gbl_prompt, _plen);
if (_len > 0) {
janet_buffer_push_bytes(&b, (uint8_t *) _buf, _len);
}
/* Erase to right */
janet_buffer_push_cstring(&b, "\x1b[0K\r");
/* Move cursor to original position. */
if (_pos + gbl_plen) {
snprintf(seq, 64, "\x1b[%dC", (int)(_pos + gbl_plen));
if (_pos + _plen) {
snprintf(seq, 64, "\x1b[%dC", (int)(_pos + _plen));
janet_buffer_push_cstring(&b, seq);
}
if (write_console((char *) b.data, b.count) == -1) {
@@ -414,7 +432,8 @@ static int insert(char c, int draw) {
gbl_buf[gbl_pos++] = c;
gbl_buf[++gbl_len] = '\0';
if (draw) {
if (gbl_plen + gbl_len < gbl_cols) {
int _plen = getplen();
if (_plen + gbl_len < gbl_cols) {
/* Avoid a full update of the line in the
* trivial case. */
if (write_console(&c, 1) == -1) return -1;
@@ -925,11 +944,12 @@ static int line() {
gbl_len = 0;
gbl_pos = 0;
while (gbl_prompt[gbl_plen]) gbl_plen++;
int _plen = getplen();
gbl_buf[0] = '\0';
addhistory();
if (write_console((char *) gbl_prompt, gbl_plen) == -1) return -1;
if (write_console((char *) gbl_prompt, _plen) == -1) return -1;
for (;;) {
char c;
char seq[5];