better handling of size mismatch in get() calls

include/sdskv-client.h

@@ -188,6 +188,9 @@ int sdskv_put_multi(sdskv_provider_handle_t provider,
  * If value is NULL, the call will be equivalent
  * to sdskv_length and put the length of the value in *vsize.
  *
+ * If the call returns SDSKV_ERR_SIZE, the value will be
+ * unchanged but the vsize will be set to the required size.
+ *
  * @param[in] provider provider handle
  * @param[in] db_id database id of the target database
  * @param[in] key key to lookup

include/sdskv-client.hpp

@@ -480,7 +480,16 @@ class client {
             s = length(db, key);
             object_resize(value, s);
         }
-        get(db, object_data(key), object_size(key), object_data(value), &s);
+        try {
+            get(db, object_data(key), object_size(key), object_data(value), &s);
+        } catch(exception& ex) {
+            if(ex.error() == SDSKV_ERR_SIZE) {
+                object_resize(value, s);
+                get(db, object_data(key), object_size(key), object_data(value), &s);
+            } else {
+                throw;
+            }
+        }
         object_resize(value, s);
         return true;
     }

src/sdskv-client.c

@@ -609,7 +609,7 @@ int sdskv_get(sdskv_provider_handle_t provider,
         ret = out.ret;
         *vsize = (hg_size_t)out.value.size;
 
-        if (out.value.size > 0) {
+        if (out.value.size > 0 && out.ret == SDSKV_SUCCESS) {
             memcpy(value, out.value.data, out.value.size);
         }