commit 4198bd0e2eb7ce81972a27feea2ad518b8ea39da
from: rsc <devnull@localhost>
date: Tue May 08 02:52:21 2007 UTC

fix random troff crash (Noel Hunt)

commit - e17c64a7cd5162ee586f4b1bdd797f64381859d9
commit + 4198bd0e2eb7ce81972a27feea2ad518b8ea39da
blob - b2ab175b3516ceeed9377659266b326f5bc2b26e
blob + 9ff2ebce8b2e28b33709d565f77fdb2e4f7c2c17
--- src/cmd/troff/n8.c
+++ src/cmd/troff/n8.c
@@ -400,7 +400,7 @@ static int texit(Tchar *start, Tchar *end)	/* hyphenat
 	for (i = 0; i <= nw; i++)
 		cnt[i] = '0';
 
-	for (wp = w; wp < w + nw; wp++) {
+	for (wp = w; wp+1 < w+nw; wp++) {
 		for (pp = trie[trieindex(*wp, *(wp+1))]; pp < nextpat; ) {
 			if (pp == 0		/* no trie entry */
 			 || *pp != *wp		/* no match on 1st letter */
@@ -537,5 +537,9 @@ static void fixup(void)	/* build indexes of where . a 
 
 static int trieindex(int d1, int d2)
 {
-	return 27 * (d1 == '.' ? 0 : d1 - 'a' + 1) + (d2 == '.' ? 0 : d2 - 'a' + 1);
+	int z;
+
+	z = 27 * (d1 == '.' ? 0 : d1 - 'a' + 1) + (d2 == '.' ? 0 : d2 - 'a' + 1);
+	assert(z >= 0 && z < 27*27);
+	return z;
 }