Fixed code where tests for NULL or '\0' used/assumed 0;

enter.c

@@ -49,7 +49,7 @@ static inline size_t append_argv(char **argv, size_t argc, char *arg)
 static void apply_limit(int resource, struct rlimit const *value)
 {
 	struct rlimit new_limit;
-	if (!value) {
+	if (value == NULL) {
 		if (getrlimit(resource, &new_limit)) {
 			if (errno == EINVAL) {
 				/* Skip this limit -- it is not supported. */
@@ -117,7 +117,7 @@ int enter(struct entry_settings *opts)
 	}
 	deny_new_capabilities = 1;
 
-	const char *root = opts->root ? opts->root : "/";
+	const char *root = (opts->root != NULL) ? opts->root : "/";
 
 	char resolved_root[PATH_MAX];
 	if (realpath(root, resolved_root) == NULL) {
@@ -128,7 +128,7 @@ int enter(struct entry_settings *opts)
 
 	char cwd[PATH_MAX];
 	char *workdir = opts->workdir;
-	if ((!workdir || workdir[0] == '\0')) {
+	if ((workdir == NULL || workdir[0] == '\0')) {
 		if (getcwd(cwd, sizeof (cwd)) == NULL) {
 			err(1, "getcwd");
 		}
@@ -149,7 +149,7 @@ int enter(struct entry_settings *opts)
 	}
 	/* Our tentative to use the cwd failed, or it worked and the cwd _is_ the
 	   new root. In both cases, the workdir must be /. */
-	if (!workdir || workdir[0] == '\0') {
+	if (workdir == NULL || workdir[0] == '\0') {
 		workdir = "/";
 	}
 
@@ -180,7 +180,7 @@ int enter(struct entry_settings *opts)
 		err(1, "could not make / private: mount");
 	}
 
-	if (opts->arch && opts->arch[0] != 0) {
+	if (opts->arch != NULL && opts->arch[0] != '\0') {
 		setarch(opts->arch);
 	}
 
@@ -217,7 +217,7 @@ int enter(struct entry_settings *opts)
 	}
 
 	if (pid) {
-		if (opts->pidfile) {
+		if (opts->pidfile != NULL) {
 			int pidfile = open(opts->pidfile, O_WRONLY | O_CREAT | O_CLOEXEC | O_NOCTTY , 0666);
 			if (pidfile == -1) {
 				err(1, "open %s", opts->pidfile);
@@ -340,7 +340,7 @@ int enter(struct entry_settings *opts)
 		}
 	}
 
-	if (opts->setup_program) {
+	if (opts->setup_program != NULL) {
 		pid_t pid = fork();
 		if (pid == -1) {
 			err(1, "setup: fork");
@@ -358,7 +358,7 @@ int enter(struct entry_settings *opts)
 			extern char **environ;
 
 			char *const *argv = default_argv;
-			if (opts->setup_argv) {
+			if (opts->setup_argv != NULL) {
 				argv = opts->setup_argv;
 			}
 
@@ -416,23 +416,23 @@ int enter(struct entry_settings *opts)
 	}
 
 	/* Set the host and domain names only when in an UTS namespace. */
-	if ((opts->hostname || opts->domainname) && !uts_unshare) {
+	if ((opts->hostname != NULL || opts->domainname != NULL ) && !uts_unshare) {
 		errx(1, "attempted to set host or domain names on the host UTS namespace.");
 	}
 
 	const char *hostname = opts->hostname;
-	if (!hostname && uts_unshare) {
+	if (hostname == NULL && uts_unshare) {
 		hostname = "localhost";
 	}
-	if (hostname && sethostname(hostname, strlen(hostname)) == -1) {
+	if (hostname != NULL && sethostname(hostname, strlen(hostname)) == -1) {
 		err(1, "sethostname");
 	}
 
 	const char *domainname = opts->domainname;
-	if (!domainname && uts_unshare) {
+	if (domainname == NULL && uts_unshare) {
 		domainname = "localdomain";
 	}
-	if (domainname && setdomainname(domainname, strlen(domainname)) == -1) {
+	if (domainname != NULL && setdomainname(domainname, strlen(domainname)) == -1) {
 		err(1, "setdomainname");
 	}
 
@@ -588,7 +588,7 @@ int enter(struct entry_settings *opts)
 		argc = append_argv(argv, argc, opts->argv[0]);
 		argc = append_argv(argv, argc, (char *) opts->pathname);
 		char *const *arg = opts->argv + 1;
-		for (; *arg; ++arg) {
+		for (; *arg != NULL; ++arg) {
 			argc = append_argv(argv, argc, *arg);
 		}
 		argv[argc] = NULL;

main.c

@@ -120,7 +120,7 @@ static void process_share(const char **out, const char *optarg)
 		append_nsname = false;
 	}
 
-	for (; share; share = strtok(NULL, ",")) {
+	for (; share != NULL; share = strtok(NULL, ",")) {
 		process_nslist_entry(out, share, path, append_nsname);
 	}
 }
@@ -136,7 +136,7 @@ static void process_persist(const char **out, const char *optarg)
 	/* Specifying a standalone path means that all namespaces should be persisted
 	   into nsfs files relative to that directory path. */
 	char all_namespaces[] = ALL_NAMESPACES;
-	if (!path) {
+	if (path == NULL) {
 		path = nsnames;
 		nsnames = all_namespaces;
 	}
@@ -148,7 +148,7 @@ static void process_persist(const char **out, const char *optarg)
 	const char *share = strtok(nsnames, ",");
 	bool multiple = share + strlen(share) != nsnames + nsnames_len;
 
-	for (; share; share = strtok(NULL, ",")) {
+	for (; share != NULL; share = strtok(NULL, ",")) {
 		process_nslist_entry(out, share, path, multiple);
 	}
 }
@@ -162,7 +162,7 @@ static void process_unshare(const char **out, char *nsnames)
 		nsnames = all_namespaces;
 	}
 
-	for (const char *ns = strtok(nsnames, ","); ns; ns = strtok(NULL, ",")) {
+	for (const char *ns = strtok(nsnames, ","); ns != NULL; ns = strtok(NULL, ",")) {
 		process_nslist_entry(out, ns, NULL, false);
 	}
 }
@@ -370,7 +370,7 @@ int main(int argc, char *argv[], char *envp[])
 				break;
 
 			case OPTION_GROUPS:
-				for (char *grp = strtok(optarg, ","); grp; grp = strtok(NULL, ",")) {
+				for (char *grp = strtok(optarg, ","); grp != NULL; grp = strtok(NULL, ",")) {
 					if (opts.ngroups >= NGROUPS_MAX) {
 						errx(1, "can only be part of a maximum of %d groups", NGROUPS_MAX);
 					}
@@ -746,7 +746,7 @@ int main(int argc, char *argv[], char *envp[])
 		++argv0;
 	}
 
-	new_argv[0] = argv0 ? argv0 : argv[optind];
+	new_argv[0] = (argv0 != NULL) ? argv0 : argv[optind];
 	for (int i = 1; i < argc - optind; ++i) {
 		new_argv[i] = argv[optind + i];
 	}
@@ -756,7 +756,7 @@ int main(int argc, char *argv[], char *envp[])
 	opts.argv = new_argv;
 	opts.envp = newenv;
 
-	if (opts.workdir && opts.workdir[0] != '\0' && opts.workdir[0] != '/') {
+	if (opts.workdir != NULL && opts.workdir[0] != '\0' && opts.workdir[0] != '/') {
 		errx(1, "workdir must be an absolute path.");
 	}
 

mount.c

@@ -81,38 +81,38 @@ static void update_mount_flags_and_options(unsigned long *mountflags, char *opts
 		{ "suid",          MS_NOSUID },
 	};
 
-	if (!opts) {
+	if (opts == NULL) {
 		return;
 	}
 
 	char sentinel;
 	char *newopts = opts;
-	for (char *opt = opts, *delim = &sentinel; delim && *opt; opt = delim + 1) {
+	for (char *opt = opts, *delim = &sentinel; delim != NULL && *opt != '\0'; opt = delim + 1) {
 
 		*delim = ',';
 		delim = strchr(opt, ',');
-		if (delim) {
-			*delim = 0;
+		if (delim != NULL) {
+			*delim = '\0';
 		}
 
 		struct mntflag *found;
 
 		found = bsearch(opt, flags, lengthof(flags), sizeof (*flags), cmpflags);
-		if (found) {
+		if (found != NULL) {
 			*mountflags |= found->flag;
 			continue;
 		}
 
 		found = bsearch(opt, neg_flags, lengthof(neg_flags), sizeof (*neg_flags), cmpflags);
-		if (found) {
+		if (found != NULL) {
 			*mountflags &= ~found->flag;
 			continue;
 		}
 
 		if (newopts > opts) {
 			*(newopts++) = ',';
 		}
-		for (char *s = opt; *s; ++s, ++newopts) {
+		for (char *s = opt; *s != '\0'; ++s, ++newopts) {
 			*newopts = *s;
 		}
 	}

path.c

@@ -21,14 +21,14 @@ void cleanpath(char *path) {
 	char *out = path;
 	char *start = path;
 
-	while (*path) {
+	while (*path != '\0') {
 		if (*path == '/') {
 			// empty component
 			++path;
-		} else if (*path == '.' && (!*(path+1) || *(path+1) == '/')) {
+		} else if (*path == '.' && (*(path+1) == '\0' || *(path+1) == '/')) {
 			// . component
 			++path;
-		} else if (*path == '.' && *(path+1) == '.' && (!*(path+2) || *(path+2) == '/')) {
+		} else if (*path == '.' && *(path+1) == '.' && (*(path+2) == '\0' || *(path+2) == '/')) {
 			// .. component
 			path += 2;
 
@@ -44,7 +44,7 @@ void cleanpath(char *path) {
 				*out = '/';
 				++out;
 			}
-			for (; *path && *path != '/'; ++path, ++out) {
+			for (; *path != '\0' && *path != '/'; ++path, ++out) {
 				*out = *path;
 			}
 		}

setarch.c

@@ -22,16 +22,15 @@ struct exec_domain {
 void setarch(const char *arch)
 {
 	static struct exec_domain domains[] = {
-		/* Placeholder for host execution domain */
-		{ "", 0 },
+		{ "", 0 },                      /* Placeholder for host execution domain */
 		{ "linux32", PER_LINUX32 },
 		{ "linux64", PER_LINUX },
 		{ "x86_64",  PER_LINUX },
 		{ "i386",    PER_LINUX32 },
 		{ "i486",    PER_LINUX32 },
 		{ "i586",    PER_LINUX32 },
 		{ "i686",    PER_LINUX32 },
-		{ "", 0 }
+		{ "", 0 }                       /* Entry to mark end of the list */
 	};
 
 	struct exec_domain *host_domain = &domains[0];
@@ -49,13 +48,13 @@ void setarch(const char *arch)
 #endif
 
 	struct exec_domain *domain = domains;
-	for (; *domain->name; ++domain) {
+	for (; *domain->name != '\0'; ++domain) {
 		if (strncmp(domain->name, arch, MACHINE_SIZE) == 0) {
 			break;
 		}
 	}
 
-	if (!*domain->name) {
+	if (*domain->name == '\0') {
 		errx(1, "setarch: unknown arch %s.", arch);
 	}
 

unpersist.c

@@ -188,7 +188,7 @@ int main(int argc, char *argv[])
 	static struct option options[] = {
 		{ "help",       no_argument,        NULL,   'h' },
 		{ "no-unlink",  no_argument,        NULL,   OPTION_NO_UNLINK },
-		{ 0, 0, 0, 0 }
+		{ NULL, 0, NULL, 0 }
 	};
 
 	static struct {

userns.c

@@ -68,7 +68,7 @@ void id_map_parse(id_map map, char *opt)
 	size_t i = 0;
 	char *saveptr;
 	char *rangestr = strtok_r(opt, ",", &saveptr);
-	for (; rangestr; rangestr = strtok_r(NULL, ",", &saveptr)) {
+	for (; rangestr != NULL; rangestr = strtok_r(NULL, ",", &saveptr)) {
 		uint32_t inner = id_parse(strtok(rangestr, ":"), "inner id range start");
 		uint32_t outer = id_parse(strtok(NULL, ":"), "outer id range start");
 		uint32_t length = id_parse(strtok(NULL, ""), "id range length");
@@ -106,7 +106,7 @@ void id_map_load_subids(id_map map, const char *subid_path, const struct id *id)
 	size_t range = id_map_append(map, 0, 0, id->id, 1);
 
 	FILE *subids = fopen(subid_path, "r");
-	if (!subids) {
+	if (subids == NULL) {
 		return;
 	}
 
@@ -121,7 +121,7 @@ void id_map_load_subids(id_map map, const char *subid_path, const struct id *id)
 	   size assumptions tend to bite back, and pages are extremely cheap. */
 	char line[4096];
 
-	while (fgets(line, sizeof (line), subids)) {
+	while (fgets(line, sizeof (line), subids) != NULL) {
 		char entryname[ID_STR_MAX + 1];
 		entryname[ID_STR_MAX] = 0;
 
@@ -220,7 +220,7 @@ void id_map_load_procids(id_map map, const char *procid_path)
 	memset(map, 0, sizeof (id_map));
 
 	char line[4096];
-	while (fgets(line, sizeof (line), subids)) {
+	while (fgets(line, sizeof (line), subids) != NULL) {
 		uint32_t inner, outer, len;
 
 		int items = sscanf(line, "%" PRIu32 "%" PRIu32 "%" PRIu32 "\n", &inner, &outer, &len);
@@ -458,7 +458,7 @@ struct id id_load_user(uid_t uid)
 	struct id id;
 	struct passwd *passwd = getpwuid(uid);
 	id.id = (uint32_t) uid;
-	id.name = passwd ? passwd->pw_name : NULL;
+	id.name = (passwd != NULL) ? passwd->pw_name : NULL;
 	return id;
 }
 
@@ -467,6 +467,6 @@ struct id id_load_group(gid_t gid)
 	struct id id;
 	struct group *group = getgrgid(gid);
 	id.id = (uint32_t) gid;
-	id.name = group ? group->gr_name : NULL;
+	id.name = (group != NULL) ? group->gr_name : NULL;
 	return id;
 }