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authorGlauber Campinho <[email protected]>2017-08-29 01:22:54 +0200
committerGlauber Campinho <[email protected]>2017-09-01 22:50:00 +0200
commit1e57f7471d60d60d9c837051d4625a35d779c520 (patch)
treea4d318c5dd5e14bf797b49ba830b69c7053be9d7
parent145f2e9cc5ce4970ca82bb517d0b0a9860db5afd (diff)
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Make cp_pos_to_col function aware of the ANSI escape codes
This fixes the issue with the function `move_cursor` described in #1536 and that causes the bug described in https://github.com/elixir-lang/elixir/issues/6504. The function `cp_pos_to_col` maps the current position in the buffer to the correct column on the screen, but it didn't handle ANSI escape codes. Since the ANSI escape codes aren't visible, the `cp_pos_to_col` now skips them when executing the calculations using `ansi_escape_width`. This new function only considers color escape codes, but also handles invalid codes.
-rw-r--r--erts/emulator/drivers/unix/ttsl_drv.c68
1 files changed, 53 insertions, 15 deletions
diff --git a/erts/emulator/drivers/unix/ttsl_drv.c b/erts/emulator/drivers/unix/ttsl_drv.c
index f3c1aa1c4a..3d007173c4 100644
--- a/erts/emulator/drivers/unix/ttsl_drv.c
+++ b/erts/emulator/drivers/unix/ttsl_drv.c
@@ -1095,6 +1095,7 @@ static int insert_buf(byte *s, int n)
ch = 0;
} while (lpos % 8);
} else if (ch == '\e') {
+ DEBUGLOG(("insert_buf: ANSI Escape: \\e"));
lbuf[lpos++] = (CONTROL_TAG | ((Uint32) ch));
} else if (ch == '\n' || ch == '\r') {
write_buf(lbuf + buffpos, lpos - buffpos);
@@ -1156,7 +1157,7 @@ static int write_buf(Uint32 *s, int n)
--n; s++;
}
} else if (*s == (CONTROL_TAG | ((Uint32) '\e'))) {
- outc('\e');
+ outc(lastput = '\e');
--n;
++s;
} else if (*s & CONTROL_TAG) {
@@ -1251,26 +1252,63 @@ static int move_cursor(int from_pos, int to_pos)
return to_col-from_col;
}
-static int cp_pos_to_col(int cp_pos)
+/*
+ * Returns the length of an ANSI escape code in a buffer, this function only consider
+ * color escape sequences like `\e[33m` or `\e[21;33m`. If a sequence has no valid
+ * terminator, the length is equal the number of characters between `\e` and the first
+ * invalid character, inclusive.
+ */
+
+static int ansi_escape_width(Uint32 *s, int max_length)
{
-#ifdef HAVE_WCWIDTH
int i;
- int col = 0;
-
- for (i = 0; i < cp_pos; i++) {
- int w = wcwidth(lbuf[i]);
- if (w > 0) {
- col += w;
- }
+
+ if (*s != (CONTROL_TAG | ((Uint32) '\e'))) {
+ return 0;
+ } else if (max_length <= 1) {
+ return 1;
+ } else if (s[1] != '[') {
+ return 2;
}
- return col;
-#else
+
+ for (i = 2; i < max_length && (s[i] == ';' || (s[i] >= '0' && s[i] <= '9')); i++);
+
+ return i + 1;
+}
+
+static int cp_pos_to_col(int cp_pos)
+{
/*
- * We dont' have any character width information. Assume that
- * code points are one column wide.
+ * If we don't have any character width information. Assume that
+ * code points are one column wide
*/
- return cp_pos;
+ int w = 1;
+ int col = 0;
+ int i = 0;
+ int j;
+
+ if (cp_pos > llen) {
+ col += cp_pos - llen;
+ cp_pos = llen;
+ }
+
+ while (i < cp_pos) {
+ j = ansi_escape_width(lbuf + i, llen - i);
+
+ if (j > 0) {
+ i += j;
+ } else {
+#ifdef HAVE_WCWIDTH
+ w = wcwidth(lbuf[i]);
#endif
+ if (w > 0) {
+ col += w;
+ }
+ i++;
+ }
+ }
+
+ return col;
}
static int start_termcap(void)