--- a/libcoding/gsm7_encode.c	Thu Aug 31 23:03:38 2023 +0000
+++ b/libcoding/gsm7_encode.c	Sat Sep 02 19:22:05 2023 +0000
@@ -4,10 +4,40 @@
  */
 
 #include <sys/types.h>
+#include <ctype.h>
 
 extern u_char gsm7_encode_table[256];
 
-latin1_to_gsm7(inbuf, outbuf, outmax, outlenp)
+static unsigned
+handle_escape(ipp)
+	u_char **ipp;
+{
+	unsigned c;
+
+	c = *(*ipp)++;
+	if (c >= '0' && c <= '7' && isxdigit(**ipp)) {
+		c = ((c - '0') << 4) | decode_hex_digit(*(*ipp)++);
+		return c;
+	}
+	switch (c) {
+	case 'n':
+		return '\n';
+	case 'r':
+		return '\r';
+	case 'e':
+		return 0x1B;
+	case 'E':		/* Euro currency symbol */
+		return 0xE5;
+	case '"':
+	case '\\':
+		c = gsm7_encode_table[c];
+		return c;
+	default:
+		return 0xFF;
+	}
+}
+
+latin1_to_gsm7(inbuf, outbuf, outmax, outlenp, allow_escape)
 	u_char *inbuf, *outbuf;
 	unsigned outmax, *outlenp;
 {
@@ -15,9 +45,15 @@
 	unsigned outcnt = 0, c, n;
 
 	while (c = *ip++) {
-		c = gsm7_encode_table[c];
-		if (c == 0xFF)
-			return(-1);
+		if (c == '\\' && allow_escape) {
+			c = handle_escape(&ip);
+			if (c == 0xFF)
+				return(-3);
+		} else {
+			c = gsm7_encode_table[c];
+			if (c == 0xFF)
+				return(-1);
+		}
 		if (c & 0x80)
 			n = 2;
 		else