In fs_lookup(), use stat(2) rather than access(2) to check file existence.

Some mildly broken real-world packages on some operating systems
contain dangling symlinks in manual page directories: pestering the
user to run makewhatis(8) makes no sense because that won't help.
On the other hand, missing read permissions deserve ugly error messages
and are unlikely to occur in practice anyway.

Fixing an issue reported by Lorenzo Beretta <loreb at github>
as part of https://github.com/void-linux/void-packages/issues/9868 .

1 files changed, 12 insertions, 7 deletions

diff --git a/main.c b/main.c
index fbb7bf28..bfe918b8 100644
--- a/main.c
+++ b/main.c
@@ -1,4 +1,4 @@
-/*	$Id: main.c,v 1.325 2019/05/03 16:14:42 schwarze Exp $ */
+/*	$Id: main.c,v 1.326 2019/05/03 17:31:15 schwarze Exp $ */
 /*
  * Copyright (c) 2008-2012 Kristaps Dzonsons <kristaps@bsd.lv>
  * Copyright (c) 2010-2012, 2014-2019 Ingo Schwarze <schwarze@openbsd.org>
@@ -21,6 +21,7 @@
 #include <sys/types.h>
 #include <sys/ioctl.h>
 #include <sys/param.h>	/* MACHINE */
+#include <sys/stat.h>
 #include <sys/wait.h>
 
 #include <assert.h>
@@ -713,6 +714,7 @@ fs_lookup(const struct manpaths *paths, size_t ipath,
 	const char *sec, const char *arch, const char *name,
 	struct manpage **res, size_t *ressz)
 {
+	struct stat	 sb;
 	glob_t		 globinfo;
 	struct manpage	*page;
 	char		*file;
@@ -722,13 +724,13 @@ fs_lookup(const struct manpaths *paths, size_t ipath,
 	form = FORM_SRC;
 	mandoc_asprintf(&file, "%s/man%s/%s.%s",
 	    paths->paths[ipath], sec, name, sec);
-	if (access(file, R_OK) != -1)
+	if (stat(file, &sb) != -1)
 		goto found;
 	free(file);
 
 	mandoc_asprintf(&file, "%s/cat%s/%s.0",
 	    paths->paths[ipath], sec, name);
-	if (access(file, R_OK) != -1) {
+	if (stat(file, &sb) != -1) {
 		form = FORM_CAT;
 		goto found;
 	}
@@ -737,7 +739,7 @@ fs_lookup(const struct manpaths *paths, size_t ipath,
 	if (arch != NULL) {
 		mandoc_asprintf(&file, "%s/man%s/%s/%s.%s",
 		    paths->paths[ipath], sec, arch, name, sec);
-		if (access(file, R_OK) != -1)
+		if (stat(file, &sb) != -1)
 			goto found;
 		free(file);
 	}
@@ -751,13 +753,16 @@ fs_lookup(const struct manpaths *paths, size_t ipath,
 	if (globres == 0)
 		file = mandoc_strdup(*globinfo.gl_pathv);
 	globfree(&globinfo);
-	if (globres == 0)
-		goto found;
+	if (globres == 0) {
+		if (stat(file, &sb) != -1)
+			goto found;
+		free(file);
+	}
 	if (res != NULL || ipath + 1 != paths->sz)
 		return 0;
 
 	mandoc_asprintf(&file, "%s.%s", name, sec);
-	globres = access(file, R_OK);
+	globres = stat(file, &sb);
 	free(file);
 	return globres != -1;