[core] quiet compiler warnings

cast away signedness warning in request_check_hostname()
mod_gnutls https_add_ssl_client_entries crts allocated if crt_size != 0
  (which is already checked earlier in routine)

report from FaceBook Infer static analysis tool (https://fbinfer.com/)
- quiet dead store warnings
- check return != NULL from allocation funcs

src/fdevent.c

@@ -1122,7 +1122,7 @@ __attribute_cold__ /*(convenience routine for use at config at startup)*/
 char *
 fdevent_load_file (const char * const fn, off_t *lim, log_error_st *errh, void *(malloc_fn)(size_t), void(free_fn)(void *))
 {
-    int fd = -1;
+    int fd;
     off_t sz = 0;
     char *buf = NULL;
     do {
@@ -1175,7 +1175,7 @@ fdevent_load_file (const char * const fn, off_t *lim, log_error_st *errh, void *
 int
 fdevent_load_file_bytes (char * const buf, const off_t sz, off_t off, const char * const fn, log_error_st *errh)
 {
-    int fd = -1;
+    int fd;
     do {
         fd = fdevent_open_cloexec(fn, 1, O_RDONLY, 0); /*(1: follows symlinks)*/
         if (fd < 0) break;

src/gw_backend.c

@@ -498,7 +498,6 @@ static int gw_spawn_connection(gw_host * const host, gw_proc * const proc, log_e
         /* server is not up, spawn it  */
         char_array env;
         uint32_t i;
-        int dfd = -1;
 
         /* reopen socket */
         gw_fd = fdevent_socket_cloexec(proc->saddr->sa_family, SOCK_STREAM, 0);
@@ -580,7 +579,7 @@ static int gw_spawn_connection(gw_host * const host, gw_proc * const proc, log_e
             env.ptr[env.used] = NULL;
         }
 
-        dfd = fdevent_open_dirname(host->args.ptr[0], 1); /* permit symlinks */
+        int dfd = fdevent_open_dirname(host->args.ptr[0], 1);/*permit symlinks*/
         if (-1 == dfd) {
             log_perror(errh, __FILE__, __LINE__,
               "open dirname failed: %s", host->args.ptr[0]);
@@ -768,6 +767,7 @@ static int parse_binpath(char_array *env, const buffer *b) {
             if (env->size == env->used) {
                 env->size += 16;
                 env->ptr = realloc(env->ptr, env->size * sizeof(*env->ptr));
+                force_assert(env->ptr);
             }
 
             c = b->ptr[i];

src/mod_cgi.c

@@ -616,7 +616,6 @@ static int cgi_create_env(request_st * const r, plugin_data * const p, handler_c
 	char *args[3];
 	int to_cgi_fds[2];
 	int from_cgi_fds[2];
-	int dfd = -1;
 	UNUSED(p);
 
 	if (!buffer_is_blank(cgi_handler)) {
@@ -683,7 +682,7 @@ static int cgi_create_env(request_st * const r, plugin_data * const p, handler_c
 		args[i  ] = NULL;
 	}
 
-	dfd = fdevent_open_dirname(r->physical.path.ptr, r->conf.follow_symlink);
+	int dfd = fdevent_open_dirname(r->physical.path.ptr,r->conf.follow_symlink);
 	if (-1 == dfd) {
 		log_perror(r->conf.errh, __FILE__, __LINE__, "open dirname %s failed", r->physical.path.ptr);
 	}

src/mod_cml_lua.c

@@ -102,7 +102,7 @@ static int cache_export_get_params(lua_State *L, int tbl, buffer *qrystr) {
 
 int cache_parse_lua(request_st * const r, plugin_data * const p, const buffer * const fn) {
 	lua_State *L;
-	int ret = -1;
+	int ret;
 	buffer *b;
 
 	b = buffer_init();

src/mod_deflate.c

@@ -624,6 +624,7 @@ static encparms * mod_deflate_parse_params(const array * const a, log_error_st *
 static uint16_t * mod_deflate_encodings_to_flags(const array *encodings) {
     if (encodings->used) {
         uint16_t * const x = calloc(encodings->used+1, sizeof(short));
+        force_assert(x);
         int i = 0;
         for (uint32_t j = 0; j < encodings->used; ++j) {
           #if defined(USE_ZLIB) || defined(USE_BZ2LIB) || defined(USE_BROTLI) \
@@ -661,6 +662,7 @@ static uint16_t * mod_deflate_encodings_to_flags(const array *encodings) {
     else {
         /* default encodings */
         uint16_t * const x = calloc(4+1, sizeof(short));
+        force_assert(x);
         int i = 0;
       #ifdef USE_ZSTD
         x[i++] = HTTP_ACCEPT_ENCODING_ZSTD;

src/mod_expire.c

@@ -42,7 +42,7 @@ FREE_FUNC(mod_expire_free) {
 
 static time_t mod_expire_get_offset(log_error_st *errh, const buffer *expire, time_t *offset) {
 	char *ts;
-	time_t type = -1;
+	time_t type;
 	time_t retts = 0;
 
 	/*

src/mod_extforward.c

@@ -889,7 +889,7 @@ static handler_t mod_extforward_Forwarded (request_st * const r, plugin_data * c
             break;
         }
     }
-    i = ++j;
+    i = j+1;
 
     if (-1 != oproto) {
         /* remove trailing spaces/tabs, and double-quotes from proto

src/mod_gnutls.c

@@ -2817,7 +2817,7 @@ https_add_ssl_client_entries (request_st * const r, handler_ctx * const hctx)
 {
     gnutls_session_t ssl = hctx->ssl;
     unsigned int crt_size = 0;
-    const gnutls_datum_t *crts;
+    const gnutls_datum_t *crts = NULL;
     buffer *vb = http_header_env_set_ptr(r, CONST_STR_LEN("SSL_CLIENT_VERIFY"));
 
     if (hctx->verify_status != ~0u)
@@ -2839,7 +2839,7 @@ https_add_ssl_client_entries (request_st * const r, handler_ctx * const hctx)
     gnutls_x509_crt_t crt;
     if (gnutls_x509_crt_init(&crt) < 0)
         return;
-    if (gnutls_x509_crt_import(crt, &crts[0], GNUTLS_X509_FMT_DER) < 0) {
+    if (crts && gnutls_x509_crt_import(crt, &crts[0], GNUTLS_X509_FMT_DER) < 0){
         gnutls_x509_crt_deinit(crt);
         return;
     }

src/mod_magnet_cache.c

@@ -101,6 +101,7 @@ static script *script_cache_new_script(script_cache * const cache, const buffer
     if (cache->used == cache->size) {
         cache->size += 16;
         cache->ptr = realloc(cache->ptr, cache->size * sizeof(*(cache->ptr)));
+        force_assert(cache->ptr);
     }
     cache->ptr[cache->used++] = sc;
 

src/mod_uploadprogress.c

@@ -65,6 +65,7 @@ static int request_map_insert(request_map *rm, request_st * const r, const char
 		rm->size = rm->size ? (rm->size << 1) : 16;
 		force_assert(rm->size);
 		rm->ptr = realloc(rm->ptr, rm->size * sizeof(*(rm->ptr)));
+		force_assert(rm->ptr);
 		memset(rm->ptr+rm->used, 0, (rm->size - rm->used)*sizeof(*(rm->ptr)));
 	}
 
@@ -73,6 +74,7 @@ static int request_map_insert(request_map *rm, request_st * const r, const char
 		rme = rm->ptr[rm->used];
 	} else {
 		rme = malloc(sizeof(*rme));
+		force_assert(rme);
 		rme->r_id = buffer_init();
 	}
 	buffer_copy_string_len(rme->r_id, r_id, idlen);

src/mod_vhostdb.c

@@ -54,6 +54,7 @@ vhostdb_cache_entry_init (const buffer * const server_name, const buffer * const
     const uint32_t dlen = buffer_clen(docroot);
     vhostdb_cache_entry * const ve =
       malloc(sizeof(vhostdb_cache_entry) + slen + dlen);
+    force_assert(ve);
     ve->ctime = log_monotonic_secs;
     ve->slen = slen;
     ve->dlen = dlen;

src/request.c

@@ -36,7 +36,7 @@ static int request_check_hostname(buffer * const host) {
     if (*h != '[') {
         uint32_t len = buffer_clen(host);
         const char * const colon = memchr(h, ':', len);
-        uint32_t hlen = colon ? (colon - h) : len;
+        uint32_t hlen = colon ? (uint32_t)(colon - h) : len;
 
         /* if hostname ends in ".", strip it */
         if (__builtin_expect( (0 == hlen), 0)) return -1;

src/stat_cache.c

@@ -1334,7 +1334,7 @@ stat_cache_entry * stat_cache_get_entry(const buffer * const name) {
 			stat_cache_entry_free(sptree->data);
 			sptree->data = sce;
 		} else {
-			sptree = sc.files = splaytree_insert(sptree, file_ndx, sce);
+			/*sptree =*/ sc.files = splaytree_insert(sptree, file_ndx, sce);
 		}
 
 	} else {