From 1e57f7471d60d60d9c837051d4625a35d779c520 Mon Sep 17 00:00:00 2001
From: Glauber Campinho <glauber.campinho@soundcloud.com>
Date: Tue, 29 Aug 2017 01:22:54 +0200
Subject: 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.
---
erts/emulator/drivers/unix/ttsl_drv.c | 68 +++++++++++++++++++++++++++--------
1 file changed, 53 insertions(+), 15 deletions(-)
(limited to 'erts')
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)
--
cgit v1.2.3
From c128db95440cc4caf34cbad5e91e1e26bb5fa6a3 Mon Sep 17 00:00:00 2001
From: Glauber Campinho <glauber.campinho@soundcloud.com>
Date: Fri, 1 Sep 2017 15:12:48 +0200
Subject: Fix del_chars not considering wide chars and update buffer length
before calling write_buf
After deleting the chars the function `del_chars` was considering the code points to move the cursor back and not the graphemes
---
erts/emulator/drivers/unix/ttsl_drv.c | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)
(limited to 'erts')
diff --git a/erts/emulator/drivers/unix/ttsl_drv.c b/erts/emulator/drivers/unix/ttsl_drv.c
index 3d007173c4..2a508b02eb 100644
--- a/erts/emulator/drivers/unix/ttsl_drv.c
+++ b/erts/emulator/drivers/unix/ttsl_drv.c
@@ -936,10 +936,10 @@ static int put_chars(byte *s, int l)
int n;
n = insert_buf(s, l);
+ if (lpos > llen)
+ llen = lpos;
if (n > 0)
write_buf(lbuf + lpos - n, n);
- if (lpos > llen)
- llen = lpos;
return TRUE;
}
@@ -1016,7 +1016,7 @@ static int del_chars(int n)
outc(' ');
move_left(1);
}
- move_cursor(llen + l, lpos);
+ move_cursor(llen + gcs, lpos);
}
else if (pos < lpos) {
l = lpos - pos; /* Buffer characters */
@@ -1036,7 +1036,7 @@ static int del_chars(int n)
outc(' ');
move_left(1);
}
- move_cursor(llen + l, lpos);
+ move_cursor(llen + gcs, lpos);
}
return TRUE;
}
@@ -1289,7 +1289,7 @@ static int cp_pos_to_col(int cp_pos)
if (cp_pos > llen) {
col += cp_pos - llen;
- cp_pos = llen;
+ cp_pos = llen;
}
while (i < cp_pos) {
--
cgit v1.2.3