avoid problems if one file is prefix of another (from mann@su-pescadero.arpa)

SCCS-vsn: usr.bin/diff/diff/diffreg.c 4.16

diff --git a/usr/src/usr.bin/diff/diff/diffreg.c b/usr/src/usr.bin/diff/diff/diffreg.c
index b1afc08..a89349b 100644 (file)
--- a/usr/src/usr.bin/diff/diff/diffreg.c
+++ b/usr/src/usr.bin/diff/diff/diffreg.c
@@ -1,4 +1,4 @@
-static char sccsid[] = "@(#)diffreg.c 4.15 %G%";
+static char sccsid[] = "@(#)diffreg.c 4.16 %G%";

 
 #include "diff.h"
 /*
 
 #include "diff.h"
 /*


@@ -571,6 +571,9 @@ struct line *a;
        struct line *ai;
        register struct line *aim;
        int k;
        struct line *ai;
        register struct line *aim;
        int k;

+
+       if (n == 0)
+               return;

        for(j=1;j<=n;j*= 2)
                m = 2*j - 1;
        for(m/=2;m!=0;m/=2) {
        for(j=1;j<=n;j*= 2)
                m = 2*j - 1;
        for(m/=2;m!=0;m/=2) {