Merge branch 'dgud/stdlib/edit-unicode' into maint

* dgud/stdlib/edit-unicode:
  stdlib: Improve edlin handling of unicode chars

OTP-14542

1 files changed, 50 insertions, 43 deletions

diff --git a/erts/emulator/drivers/unix/ttsl_drv.c b/erts/emulator/drivers/unix/ttsl_drv.c
index e425b99f16..bce097d944 100644
--- a/erts/emulator/drivers/unix/ttsl_drv.c
+++ b/erts/emulator/drivers/unix/ttsl_drv.c
@@ -108,16 +108,15 @@ static int lbuf_size = BUFSIZ;
 static Uint32 *lbuf;		/* The current line buffer */
 static int llen;		/* The current line length */
 static int lpos;                /* The current "cursor position" in the line buffer */
-
+                                /* NOTE: not the same as column position a char may not take a"
+                                 * column to display or it might take many columns
+                                 */
 /* 
  * Tags used in line buffer to show that these bytes represent special characters,
  * Max unicode is 0x0010ffff, so we have lots of place for meta tags... 
  */
 #define CONTROL_TAG 0x10000000U /* Control character, value in first position */
 #define ESCAPED_TAG 0x01000000U /* Escaped character, value in first position */
-#ifdef HAVE_WCWIDTH
-#define WIDE_TAG    0x02000000U /* Wide character, value in first position    */
-#endif
 #define TAG_MASK    0xFF000000U
 
 #define MAXSIZE (1 << 16)
@@ -156,6 +155,8 @@ static int insert_buf(byte*,int);
 static int write_buf(Uint32 *,int);
 static int outc(int c);
 static int move_cursor(int,int);
+static int cp_pos_to_col(int cp_pos);
+
 
 /* Termcap functions. */
 static int start_termcap(void);
@@ -991,24 +992,26 @@ static int del_chars(int n)
 {
     int i, l, r;
     int pos;
+    int gcs; /* deleted grapheme characters */
 
     update_cols();
 
     /* Step forward or backwards over n logical characters. */
     pos = step_over_chars(n);
-
+    DEBUGLOG(("del_chars: %d from %d %d %d\n", n, lpos, pos, llen));
     if (pos > lpos) {
 	l = pos - lpos;		/* Buffer characters to delete */
 	r = llen - lpos - l;	/* Characters after deleted */
+        gcs = cp_pos_to_col(pos) - cp_pos_to_col(lpos);
 	/* Fix up buffer and buffer pointers. */
 	if (r > 0)
 	    memmove(lbuf + lpos, lbuf + pos, r * sizeof(Uint32));
 	llen -= l;
 	/* Write out characters after, blank the tail and jump back to lpos. */
 	write_buf(lbuf + lpos, r);
-	for (i = l ; i > 0; --i)
+	for (i = gcs ; i > 0; --i)
 	  outc(' ');
-	if (COL(llen+l) == 0 && xn)
+	if (xn && COL(cp_pos_to_col(llen)+gcs) == 0)
 	{
 	   outc(' ');
 	   move_left(1);
@@ -1018,7 +1021,7 @@ static int del_chars(int n)
     else if (pos < lpos) {
 	l = lpos - pos;		/* Buffer characters */
 	r = llen - lpos;	/* Characters after deleted */
-	move_cursor(lpos, lpos-l);	/* Move back */
+	gcs = -move_cursor(lpos, lpos-l);	/* Move back */
 	/* Fix up buffer and buffer pointers. */
 	if (r > 0)
 	    memmove(lbuf + pos, lbuf + lpos, r * sizeof(Uint32));
@@ -1026,14 +1029,14 @@ static int del_chars(int n)
 	llen -= l;
 	/* Write out characters after, blank the tail and jump back to lpos. */
 	write_buf(lbuf + lpos, r);
-	for (i = l ; i > 0; --i)
-	  outc(' ');
-	if (COL(llen+l) == 0 && xn)
+	for (i = gcs ; i > 0; --i)
+          outc(' ');
+        if (xn && COL(cp_pos_to_col(llen)+gcs) == 0)
 	{
-	   outc(' ');
-	   move_left(1);
+          outc(' ');
+          move_left(1);
 	}
-	move_cursor(llen + l, lpos);
+        move_cursor(llen + l, lpos);
     }
     return TRUE;
 }
@@ -1047,22 +1050,12 @@ static int step_over_chars(int n)
     end = lbuf + llen;
     c = lbuf + lpos;
     for ( ; n > 0 && c < end; --n) {
-#ifdef HAVE_WCWIDTH
-	while (*c & WIDE_TAG) {
-	    c++;
-	}
-#endif
 	c++;
 	while (c < end && (*c & TAG_MASK) && ((*c & ~TAG_MASK) == 0))
 	    c++;
     }
     for ( ; n < 0 && c > beg; n++) {
 	--c;
-#ifdef HAVE_WCWIDTH
-	while (c > beg + 1 && (c[-1] & WIDE_TAG)) {
-	    --c;
-	}
-#endif
 	while (c > beg && (*c & TAG_MASK) && ((*c & ~TAG_MASK) == 0))
 	    --c;
     }
@@ -1088,15 +1081,6 @@ static int insert_buf(byte *s, int n)
 	    ++pos;
 	}
 	if ((utf8_mode && (ch >= 128 || isprint(ch))) || (ch <= 255 && isprint(ch))) {
-#ifdef HAVE_WCWIDTH
-	    int width;
-	    if ((width = wcwidth(ch)) > 1) {
-		while (--width) {
-		    DEBUGLOG(("insert_buf: Wide(UTF-8):%d,%d",width,ch));
-		    lbuf[lpos++] = (WIDE_TAG | ((Uint32) ch));
-		}
-	    }
-#endif
 	    DEBUGLOG(("insert_buf: Printable(UTF-8):%d",ch));
 	    lbuf[lpos++] = (Uint32) ch;
 	} else if (ch >= 128) { /* not utf8 mode */
@@ -1204,10 +1188,6 @@ static int write_buf(Uint32 *s, int n)
 	    if (octbuff != octtmp) {
 		driver_free(octbuff);
 	    }
-#ifdef HAVE_WCWIDTH
-	} else if (*s & WIDE_TAG) {
-	    --n; s++;
-#endif
 	} else {
 	    DEBUGLOG(("write_buf: Very unexpected character %d",(int) *s));
 	    ++n;
@@ -1216,7 +1196,7 @@ static int write_buf(Uint32 *s, int n)
     }
     /* Check landed in first column of new line and have 'xn' bug. */
     n = s - lbuf;
-    if (COL(n) == 0 && xn && n != 0) {
+    if (xn && n != 0 && COL(cp_pos_to_col(n)) == 0) {
 	if (n >= llen) {
 	    outc(' ');
 	} else if (lastput == 0) { /* A multibyte UTF8 character */
@@ -1246,14 +1226,19 @@ static int outc(int c)
     return 1;
 }
 
-static int move_cursor(int from, int to)
+static int move_cursor(int from_pos, int to_pos)
 {
+    int from_col, to_col;
     int dc, dl;
-
     update_cols();
 
-    dc = COL(to) - COL(from);
-    dl = LINE(to) - LINE(from);
+    from_col = cp_pos_to_col(from_pos);
+    to_col = cp_pos_to_col(to_pos);
+
+    dc = COL(to_col) - COL(from_col);
+    dl = LINE(to_col) - LINE(from_col);
+    DEBUGLOG(("move_cursor: from %d %d to %d %d => %d %d\n",
+              from_pos, from_col, to_pos, to_col, dl, dc));
     if (dl > 0)
       move_down(dl);
     else if (dl < 0)
@@ -1262,7 +1247,29 @@ static int move_cursor(int from, int to)
       move_right(dc);
     else if (dc < 0)
       move_left(-dc);
-    return TRUE;
+    return to_col-from_col;
+}
+
+static int cp_pos_to_col(int cp_pos)
+{
+#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;
+        }
+    }
+    return col;
+#else
+    /*
+     * We dont' have any character width information. Assume that
+     * code points are one column wide.
+     */
+    return cp_pos;
+#endif
 }
 
 static int start_termcap(void)