Reduce compiler warnungs: initialize variables, add casts to avoid overflows

Signed-off-by: Lars H. Rohwedder <RokerHRO@users.noreply.github.com>

Author: RokerHRO

cliserv.c

@@ -117,10 +117,9 @@ uint64_t ntohll(uint64_t a) {
  * @return 0 on completion, or -1 on failure
  **/
 int readit(int f, void *buf, size_t len) {
-	ssize_t res;
 	while (len > 0) {
 		DEBUG("*");
-		res = read(f, buf, len);
+		ssize_t res = read(f, buf, len);
 		if (res > 0) {
 			len -= res;
 			buf += res;

nbdsrv.c

@@ -33,8 +33,8 @@ bool address_matches(const char* mask, const struct sockaddr* addr, GError** err
 	struct addrinfo *res, *aitmp, hints;
 	char *masksep;
 	char privmask[strlen(mask)+1];
-	int masklen;
-	int addrlen = addr->sa_family == AF_INET ? 4 : 16;
+	long masklen = 0;
+	long addrlen = addr->sa_family == AF_INET ? 4 : 16;
 #define IPV4_MAP_PREFIX 12
 	uint8_t ipv4_mapped[IPV4_MAP_PREFIX+4] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
 		255, 255, 0, 0, 0, 0};

tests/code/dup.c

@@ -17,7 +17,6 @@ int stringcmp(const char* a, const char* b) {
 }
 
 int main(void) {
-	SERVER *srvd;
 	SERVER srvs = {
 		.exportname = "foo",
 		.expected_size = 0,
@@ -34,7 +33,7 @@ int main(void) {
 		.cowdir = "/tmp",
 	};
 
-	srvd = dup_serve(&srvs);
+	SERVER *srvd = dup_serve(&srvs);
 
 	count_assert(&srvs != srvd);
 	count_assert(stringcmp(srvs.exportname, srvd->exportname) == 0);

treefiles.c

@@ -18,10 +18,10 @@ void construct_path(char* name, int lenmax, off_t size, off_t pos, off_t* ppos)
 	if (lenmax<10)
 		err("Char buffer overflow. This is likely a bug.");
 
-	if (size<TREEDIRSIZE*TREEPAGESIZE) {
+	if (size<(off_t)TREEDIRSIZE*TREEPAGESIZE) {
 		// we are done, add filename
 		snprintf(name,lenmax,"/FILE%04" PRIX64,(pos/TREEPAGESIZE) % TREEDIRSIZE);
-		*ppos = pos / (TREEPAGESIZE*TREEDIRSIZE);
+		*ppos = pos / ((off_t)TREEPAGESIZE*TREEDIRSIZE);
 	} else {
 		construct_path(name+9,lenmax-9,size/TREEDIRSIZE,pos,ppos);
 		char buffer[10];