Yet^2 another fix for the line continuation bug.

The fundamental problem with the original code is that it accesses
p[-2] which is one before the beginning of the input buffer for
empty lines.  rev.1.6 just moved the problem from failures when
p[-2] happens to be '\\' to failures when it happens to be '\0'.
rev.1.5 was confused about the trailing newline and other things.

I went back to rev.1.5 and fixed it.  The result is the same as
Keith Bostic's final version in PR 1356 except it loses more
gracefully for excessively long input lines.

1 files changed, 5 insertions, 5 deletions

diff --git a/usr.bin/sed/compile.c b/usr.bin/sed/compile.c
index 7e113823a66f..c1bb8f9e89a9 100644
--- a/usr.bin/sed/compile.c
+++ b/usr.bin/sed/compile.c
@@ -615,7 +615,7 @@ compile_tr(p, transtab)
 static char *
 compile_text()
 {
-	int asize, size;
+	int asize, esc_nl, size;
 	char *text, *p, *op, *s;
 	char lbuf[_POSIX2_LINE_MAX + 1];
 
@@ -626,13 +626,13 @@ compile_text()
 		op = s = text + size;
 		p = lbuf;
 		EATSPACE();
-		for (; *p != '\0'; p++) {
-			if (*p == '\\')
-				*p++ = '\0';
+		for (esc_nl = 0; *p != '\0'; p++) {
+			if (*p == '\\' && p[1] != '\0' && *++p == '\n')
+				esc_nl = 1;
 			*s++ = *p;
 		}
 		size += s - op;
-		if (p[-2] != '\0') {
+		if (!esc_nl) {
 			*s = '\0';
 			break;
 		}