Merge of r4778, r4782, r4783, r4824, r4830, r4834: minor fixes.

*) Reorder checks in ngx_shared_memory_add() for more consistent
   error messages.

*) Added "const" to ngx_memcpy() with NGX_MEMCPY_LIMIT defined.  This
   fixes warning produced during compilation of the ngx_http_geoip_module
   due to const qualifier being discarded.

*) Fixed possible use of old cached times if runtime went backwards.

   If ngx_time_sigsafe_update() updated only ngx_cached_err_log_time, and
   then clock was adjusted backwards, the cached_time[slot].sec might
   accidentally match current seconds on next ngx_time_update() call,
   resulting in various cached times not being updated.

   Fix is to clear the cached_time[slot].sec to explicitly mark cached times
   are stale and need updating.

*) Radix tree preallocation fix.  The preallocation size was calculated
   incorrectly and was always 8 due to sizeof(ngx_radix_tree_t) accidentally
   used instead of sizeof(ngx_radix_node_t).

*) Fixed overflow if ngx_slab_alloc() is called with very big "size"
   argument.

*) Write filter: replaced unneeded loop with one to free chains.
   Noted by Gabor Lekeny.

src/core/ngx_cycle.c

@@ -1285,14 +1285,6 @@ ngx_shared_memory_add(ngx_conf_t *cf, ngx_str_t *name, size_t size, void *tag)
             continue;
         }
 
-        if (size && size != shm_zone[i].shm.size) {
-            ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
-                            "the size %uz of shared memory zone \"%V\" "
-                            "conflicts with already declared size %uz",
-                            size, &shm_zone[i].shm.name, shm_zone[i].shm.size);
-            return NULL;
-        }
-
         if (tag != shm_zone[i].tag) {
             ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
                             "the shared memory zone \"%V\" is "
@@ -1301,6 +1293,14 @@ ngx_shared_memory_add(ngx_conf_t *cf, ngx_str_t *name, size_t size, void *tag)
             return NULL;
         }
 
+        if (size && size != shm_zone[i].shm.size) {
+            ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
+                            "the size %uz of shared memory zone \"%V\" "
+                            "conflicts with already declared size %uz",
+                            size, &shm_zone[i].shm.name, shm_zone[i].shm.size);
+            return NULL;
+        }
+
         return &shm_zone[i];
     }
 

src/core/ngx_radix_tree.c

@@ -60,7 +60,7 @@ ngx_radix_tree_create(ngx_pool_t *pool, ngx_int_t preallocate)
      */
 
     if (preallocate == -1) {
-        switch (ngx_pagesize / sizeof(ngx_radix_tree_t)) {
+        switch (ngx_pagesize / sizeof(ngx_radix_node_t)) {
 
         /* amd64 */
         case 128:

src/core/ngx_slab.c

@@ -162,8 +162,8 @@ ngx_slab_alloc_locked(ngx_slab_pool_t *pool, size_t size)
         ngx_log_debug1(NGX_LOG_DEBUG_ALLOC, ngx_cycle->log, 0,
                        "slab alloc: %uz", size);
 
-        page = ngx_slab_alloc_pages(pool, (size + ngx_pagesize - 1)
-                                          >> ngx_pagesize_shift);
+        page = ngx_slab_alloc_pages(pool, (size >> ngx_pagesize_shift)
+                                          + ((size % ngx_pagesize) ? 1 : 0));
         if (page) {
             p = (page - pool->pages) << ngx_pagesize_shift;
             p += (uintptr_t) pool->start;

src/core/ngx_string.c

@@ -1827,7 +1827,7 @@ ngx_sort(void *base, size_t n, size_t size,
 #if (NGX_MEMCPY_LIMIT)
 
 void *
-ngx_memcpy(void *dst, void *src, size_t n)
+ngx_memcpy(void *dst, const void *src, size_t n)
 {
     if (n > NGX_MEMCPY_LIMIT) {
         ngx_log_error(NGX_LOG_ALERT, ngx_cycle->log, 0, "memcpy %uz bytes", n);

src/core/ngx_string.h

@@ -89,7 +89,7 @@ ngx_strlchr(u_char *p, u_char *last, u_char c)
 
 #if (NGX_MEMCPY_LIMIT)
 
-void *ngx_memcpy(void *dst, void *src, size_t n);
+void *ngx_memcpy(void *dst, const void *src, size_t n);
 #define ngx_cpymem(dst, src, n)   (((u_char *) ngx_memcpy(dst, src, n)) + (n))
 
 #else

src/core/ngx_times.c

@@ -211,6 +211,10 @@ ngx_time_sigsafe_update(void)
         slot++;
     }
 
+    tp = &cached_time[slot];
+
+    tp->sec = 0;
+
     ngx_gmtime(sec + cached_gmtoff * 60, &tm);
 
     p = &cached_err_log_time[slot][0];

src/http/ngx_http_write_filter_module.c

@@ -185,23 +185,19 @@ ngx_http_write_filter(ngx_http_request_t *r, ngx_chain_t *in)
     }
 
     if (size == 0 && !(c->buffered & NGX_LOWLEVEL_BUFFERED)) {
-        if (last) {
+        if (last || flush) {
+            for (cl = r->out; cl; /* void */) {
+                ln = cl;
+                cl = cl->next;
+                ngx_free_chain(r->pool, ln);
+            }
+
             r->out = NULL;
             c->buffered &= ~NGX_HTTP_WRITE_BUFFERED;
 
             return NGX_OK;
         }
 
-        if (flush) {
-            do {
-                r->out = r->out->next;
-            } while (r->out);
-
-            c->buffered &= ~NGX_HTTP_WRITE_BUFFERED;
-
-            return NGX_OK;
-        }
-
         ngx_log_error(NGX_LOG_ALERT, c->log, 0,
                       "the http output chain is empty");