various: fix 'uninitialized when used' warnings [clang]

This change fixes "warning: variable 'var' may be uninitialized when used
here [-Wconditional-uninitialized]" warnings reported in various files.

Signed-off-by: Sami Kerola <kerolasa@iki.fi>

disk-utils/mkfs.minix.c

@@ -685,7 +685,7 @@ static int find_super_magic(const struct fs_control *ctl)
 
 static void determine_device_blocks(struct fs_control *ctl, const struct stat *statbuf)
 {
-	unsigned long long dev_blocks;
+	unsigned long long dev_blocks = 0;
 
 	if (S_ISBLK(statbuf->st_mode)) {
 		int sectorsize;

disk-utils/sfdisk.c

@@ -1724,7 +1724,7 @@ static int command_fdisk(struct sfdisk *sf, int argc, char **argv)
 
 		nparts = fdisk_table_get_nents(tb);
 		if (nparts) {
-			size_t cur_partno;
+			size_t cur_partno = (size_t) -1;
 			struct fdisk_partition *pa = fdisk_table_get_partition(tb, nparts - 1);
 
 			assert(pa);

libblkid/src/partitions/dos.c

@@ -55,7 +55,7 @@ static int parse_dos_extended(blkid_probe pr, blkid_parttable tab,
 
 	while (1) {
 		struct dos_partition *p, *p0;
-		uint32_t start, size;
+		uint32_t start = 0, size;
 
 		if (++ct_nodata > 100)
 			return BLKID_PROBE_OK;

libblkid/src/partitions/partitions.c

@@ -1010,7 +1010,7 @@ blkid_partition blkid_partlist_get_partition_by_partno(blkid_partlist ls, int n)
 blkid_partition blkid_partlist_devno_to_partition(blkid_partlist ls, dev_t devno)
 {
 	struct path_cxt *pc;
-	uint64_t start, size;
+	uint64_t start = 0, size;
 	int i, rc, partno = 0;
 
 	DBG(LOWPROBE, ul_debug("trying to convert devno 0x%llx to partition",

libblkid/src/superblocks/ddf_raid.c

@@ -78,7 +78,7 @@ static int probe_ddf(blkid_probe pr,
 	size_t i;
 	struct ddf_header *ddf = NULL;
 	char version[DDF_REV_LENGTH + 1];
-	uint64_t off, lba;
+	uint64_t off = 0, lba;
 
 	if (pr->size < 0x30000)
 		return 1;

libblkid/src/superblocks/hfs.c

@@ -191,7 +191,7 @@ static int probe_hfsplus(blkid_probe pr, const struct blkid_idmag *mag)
 	unsigned int off = 0;
 	unsigned int blocksize;
 	unsigned int cat_block;
-	unsigned int ext_block_start;
+	unsigned int ext_block_start = 0;
 	unsigned int ext_block_count;
 	unsigned int record_count;
 	unsigned int leaf_node_head;

libblkid/src/superblocks/zfs.c

@@ -218,7 +218,7 @@ static int probe_zfs(blkid_probe pr,
 	const struct blkid_idmag *mag  __attribute__((__unused__)))
 {
 	int swab_endian = 0;
-	struct zfs_uberblock *ub;
+	struct zfs_uberblock *ub = NULL;
 	loff_t offset = 0, ub_offset = 0;
 	int label_no, found = 0, found_in_label;
 	void *label;

libfdisk/src/dos.c

@@ -1708,7 +1708,7 @@ static int dos_add_partition(struct fdisk_context *cxt,
 	} else {
 		char hint[BUFSIZ];
 		struct fdisk_ask *ask;
-		int c;
+		int c = 0;
 
 		/* the default layout for scripts is to create primary partitions */
 		if (cxt->script || !fdisk_has_dialogs(cxt)) {

libfdisk/src/table.c

@@ -728,7 +728,7 @@ int fdisk_diff_tables(struct fdisk_table *a, struct fdisk_table *b,
 		      struct fdisk_iter *itr,
 		      struct fdisk_partition **res, int *change)
 {
-	struct fdisk_partition *pa, *pb;
+	struct fdisk_partition *pa = NULL, *pb;
 	int rc = 1;
 
 	assert(itr);

misc-utils/logger.c

@@ -237,7 +237,7 @@ static int pencode(char *s)
 
 static int unix_socket(struct logger_ctl *ctl, const char *path, int *socket_type)
 {
-	int fd, i, type = -1;
+	int fd = -1, i, type = -1;
 	static struct sockaddr_un s_addr;	/* AF_UNIX address of local logger */
 
 	if (strlen(path) >= sizeof(s_addr.sun_path))

misc-utils/uuidd.c

@@ -313,7 +313,8 @@ static void server_loop(const char *socket_path, const char *pidfile_path,
 	uuid_t			uu;
 	char			reply_buf[1024], *cp;
 	char			op, str[UUID_STR_LEN];
-	int			i, ns, len, num;
+	int			i, ns, len;
+	int			num;		/* intentionally uninitialized */
 	int			s = 0;
 	int			fd_pidfile = -1;
 	int			ret;

misc-utils/uuidparse.c

@@ -144,7 +144,7 @@ static void fill_table_row(struct libscols_table *tb, char const *const uuid)
 	size_t i;
 	uuid_t buf;
 	int invalid = 0;
-	int variant, type;
+	int variant = -1, type = -1;
 
 	assert(tb);
 	assert(uuid);

sys-utils/hwclock.c

@@ -954,7 +954,7 @@ manipulate_clock(const struct hwclock_control *ctl, const time_t set_time,
 		 const struct timeval startup_time, struct adjtime *adjtime)
 {
 	/* The time at which we read the Hardware Clock */
-	struct timeval read_time;
+	struct timeval read_time = { 0 };
 	/*
 	 * The Hardware Clock gives us a valid time, or at
 	 * least something close enough to fool mktime().

sys-utils/readprofile.c

@@ -136,7 +136,7 @@ int main(int argc, char **argv)
 	unsigned long long add0 = 0;
 	unsigned int step;
 	unsigned int *buf, total, fn_len;
-	unsigned long long fn_add, next_add;	/* current and next address */
+	unsigned long long fn_add = 0, next_add; /* current and next address */
 	char fn_name[S_LEN], next_name[S_LEN];	/* current and next name */
 	char mode[8];
 	int c;

sys-utils/setarch.c

@@ -266,7 +266,7 @@ int main(int argc, char *argv[])
 	int verbose = 0;
 	int archwrapper;
 	int c;
-	struct arch_domain *doms, *target;
+	struct arch_domain *doms, *target = NULL;
 	unsigned long pers_value = 0;
 	char *shell = NULL, *shell_arg = NULL;