MFC r267490:

patch: unsign the line length to avoid overflows.

Patch(1) uses a short int for the line length, which is usually
sufficient for regular diffs, but makes no effort to signal
when there is an overflow.

Change the line length to an unsigned short int to better use
the fact that a length is never negative.  The change is loosely
inspired on a related change in DragonFly, but we avoid spending
more memory than necessary.

While here adjust the messages to be clearer on what is happening.

1 files changed, 9 insertions, 5 deletions

diff --git a/usr.bin/patch/patch.c b/usr.bin/patch/patch.c
index 1743678..7a53284 100644
--- a/usr.bin/patch/patch.c
+++ b/usr.bin/patch/patch.c
@@ -742,14 +742,18 @@ abort_context_hunk(void)
 static void
 rej_line(int ch, LINENUM i)
 {
-	size_t len;
+	unsigned short len;
 	const char *line = pfetch(i);
 
-	len = strlen(line);
+	len = strnlen(line, USHRT_MAX);
 
 	fprintf(rejfp, "%c%s", ch, line);
-	if (len == 0 || line[len-1] != '\n')
-		fprintf(rejfp, "\n\\ No newline at end of file\n");
+	if (len == 0 || line[len-1] != '\n') {
+		if (len >= USHRT_MAX)
+			fprintf(rejfp, "\n\\ Line too long\n");
+		else
+			fprintf(rejfp, "\n\\ No newline at end of line\n");
+	}
 }
 
 static void
@@ -1016,7 +1020,7 @@ patch_match(LINENUM base, LINENUM offset, LINENUM fuzz)
 	LINENUM		pat_lines = pch_ptrn_lines() - fuzz;
 	const char	*ilineptr;
 	const char	*plineptr;
-	short		plinelen;
+	unsigned short	plinelen;
 
 	for (iline = base + offset + fuzz; pline <= pat_lines; pline++, iline++) {
 		ilineptr = ifetch(iline, offset >= 0);