39958: Add extra byte to PATH_MAX allocations.

This ensures we've got enough space for a null, although this
isn't always needed.

ChangeLog

@@ -1,3 +1,9 @@
+2016-11-17  Peter Stephenson  <p.w.stephenson@ntlworld.com>
+
+	* 39958: Src/Zle/compctl.c, Src/builtin.c, Src/compat.c,
+	Src/exec.c, Src/glob.c, Src/hist.c, Src/utils.c: Add spare byte
+	to PATH_MAX allocation to allow for possible null.
+
 2016-11-17  Daniel Shahaf  <d.s@daniel.shahaf.name>
 
 	* 39921: Completion/Unix/Command/_git: __git_recent_branches:

Src/Zle/compctl.c

@@ -2135,7 +2135,7 @@ gen_matches_files(int dirs, int execs, int all)
 {
     DIR *d;
     struct stat buf;
-    char *n, p[PATH_MAX], *q = NULL, *e, *pathpref;
+    char *n, p[PATH_MAX+1], *q = NULL, *e, *pathpref;
     LinkList l = NULL;
     int ns = 0, ng = opts[NULLGLOB], test, aw = addwhat, pathpreflen;
 

Src/builtin.c

@@ -973,7 +973,7 @@ cd_do_chdir(char *cnam, char *dest, int hard)
      * Normalize path under Cygwin to avoid messing with
      * DOS style names with drives in them
      */
-    static char buf[PATH_MAX];
+    static char buf[PATH_MAX+1];
 #ifdef HAVE_CYGWIN_CONV_PATH
     cygwin_conv_path(CCP_WIN_A_TO_POSIX | CCP_RELATIVE, dest, buf,
 		     PATH_MAX);

Src/compat.c

@@ -270,7 +270,7 @@ zgetdir(struct dirsav *d)
     int len;
 #endif
 
-    buf = zhalloc(bufsiz = PATH_MAX);
+    buf = zhalloc(bufsiz = PATH_MAX+1);
     pos = bufsiz - 1;
     buf[pos] = '\0';
     strcpy(nbuf, "../");
@@ -439,11 +439,11 @@ zgetcwd(void)
 	    free(cwd);
 	}
 #else
-	char *cwdbuf = zalloc(PATH_MAX);
+	char *cwdbuf = zalloc(PATH_MAX+1);
 	ret = getcwd(cwdbuf, PATH_MAX);
 	if (ret)
 	    ret = dupstring(ret);
-	zfree(cwdbuf, PATH_MAX);
+	zfree(cwdbuf, PATH_MAX+1);
 #endif /* GETCWD_CALLS_MALLOC */
     }
 #endif /* HAVE_GETCWD */

Src/exec.c

@@ -437,7 +437,7 @@ static int
 zexecve(char *pth, char **argv, char **newenvp)
 {
     int eno;
-    static char buf[PATH_MAX * 2];
+    static char buf[PATH_MAX * 2+1];
     char **eep;
 
     unmetafy(pth, NULL);
@@ -620,7 +620,7 @@ static void
 execute(LinkList args, int flags, int defpath)
 {
     Cmdnam cn;
-    char buf[MAXCMDLEN], buf2[MAXCMDLEN];
+    char buf[MAXCMDLEN+1], buf2[MAXCMDLEN+1];
     char *s, *z, *arg0;
     char **argv, **pp, **newenvp = NULL;
     int eno = 0, ee;
@@ -701,7 +701,7 @@ execute(LinkList args, int flags, int defpath)
 
     /* for command -p, search the default path */
     if (defpath) {
-	char pbuf[PATH_MAX];
+	char pbuf[PATH_MAX+1];
 	char *dptr;
 
 	if (!search_defpath(arg0, pbuf, PATH_MAX)) {
@@ -721,7 +721,7 @@ execute(LinkList args, int flags, int defpath)
     } else {
 
 	if ((cn = (Cmdnam) cmdnamtab->getnode(cmdnamtab, arg0))) {
-	    char nn[PATH_MAX], *dptr;
+	    char nn[PATH_MAX+1], *dptr;
 
 	    if (cn->node.flags & HASHED)
 		strcpy(nn, cn->u.cmd);
@@ -814,7 +814,7 @@ findcmd(char *arg0, int docopy, int default_path)
 	}
     }
     if (cn) {
-	char nn[PATH_MAX];
+	char nn[PATH_MAX+1];
 
 	if (cn->node.flags & HASHED)
 	    strcpy(nn, cn->u.cmd);
@@ -905,7 +905,7 @@ mod_export Cmdnam
 hashcmd(char *arg0, char **pp)
 {
     Cmdnam cn;
-    char *s, buf[PATH_MAX];
+    char *s, buf[PATH_MAX+1];
     char **pq;
 
     for (; *pp; pp++)
@@ -5602,7 +5602,7 @@ runshfunc(Eprog prog, FuncWrap wrap, char *name)
 Eprog
 getfpfunc(char *s, int *ksh, char **fname)
 {
-    char **pp, buf[PATH_MAX];
+    char **pp, buf[PATH_MAX+1];
     off_t len;
     off_t rlen;
     char *d;
@@ -5732,7 +5732,7 @@ cancd(char *s)
     char *t;
 
     if (*s != '/') {
-	char sbuf[PATH_MAX], **cp;
+	char sbuf[PATH_MAX+1], **cp;
 
 	if (cancd2(s))
 	    return s;

Src/glob.c

@@ -283,7 +283,7 @@ addpath(char *s, int l)
 static int
 statfullpath(const char *s, struct stat *st, int l)
 {
-    char buf[PATH_MAX];
+    char buf[PATH_MAX+1];
 
     DPUTS(strlen(s) + !*s + pathpos - pathbufcwd >= PATH_MAX,
 	  "BUG: statfullpath(): pathname too long");
@@ -779,7 +779,7 @@ parsepat(char *str)
 
     /* Now there is no (#X) in front, we can check the path. */
     if (!pathbuf)
-	pathbuf = zalloc(pathbufsz = PATH_MAX);
+	pathbuf = zalloc(pathbufsz = PATH_MAX+1);
     DPUTS(pathbufcwd, "BUG: glob changed directory");
     if (*str == '/') {		/* pattern has absolute path */
 	str++;

Src/hist.c

@@ -1843,7 +1843,7 @@ chrealpath(char **junkptr)
 # ifdef REALPATH_ACCEPTS_NULL
     char *lastpos, *nonreal, *real;
 # else
-    char *lastpos, *nonreal, pathbuf[PATH_MAX];
+    char *lastpos, *nonreal, pathbuf[PATH_MAX+1];
     char *real = pathbuf;
 # endif
 #endif

Src/utils.c

@@ -845,7 +845,7 @@ ispwd(char *s)
     return 0;
 }
 
-static char xbuf[PATH_MAX*2];
+static char xbuf[PATH_MAX*2+1];
 
 /**/
 static char **
@@ -884,7 +884,7 @@ static int
 xsymlinks(char *s, int full)
 {
     char **pp, **opp;
-    char xbuf2[PATH_MAX*3], xbuf3[PATH_MAX*2];
+    char xbuf2[PATH_MAX*3+1], xbuf3[PATH_MAX*2+1];
     int t0, ret = 0;
     zulong xbuflen = strlen(xbuf);
 
@@ -1003,7 +1003,7 @@ print_if_link(char *s, int all)
 	*xbuf = '\0';
 	if (all) {
 	    char *start = s + 1;
-	    char xbuflink[PATH_MAX];
+	    char xbuflink[PATH_MAX+1];
 	    for (;;) {
 		if (xsymlinks(start, 0) > 0) {
 		    printf(" -> ");
@@ -1140,7 +1140,7 @@ finddir(char *s)
 	if(homenode.diff==1)
 	    homenode.diff = 0;
 	if(!finddir_full)
-	    finddir_full = zalloc(ffsz = PATH_MAX);
+	    finddir_full = zalloc(ffsz = PATH_MAX+1);
 	finddir_full[0] = 0;
 	return finddir_last = NULL;
     }
@@ -1644,7 +1644,7 @@ checkmailpath(char **s)
 	} else if (S_ISDIR(st.st_mode)) {
 	    LinkList l;
 	    DIR *lock = opendir(unmeta(*s));
-	    char buf[PATH_MAX * 2], **arr, **ap;
+	    char buf[PATH_MAX * 2 + 1], **arr, **ap;
 	    int ct = 1;
 
 	    if (lock) {
@@ -6916,7 +6916,7 @@ strsfx(char *s, char *t)
 static int
 upchdir(int n)
 {
-    char buf[PATH_MAX];
+    char buf[PATH_MAX+1];
     char *s;
     int err = -1;