diff --git a/innobase/btr/btr0sea.c b/innobase/btr/btr0sea.c
index ed746bcf12c..3c202c5a3bf 100644
--- a/innobase/btr/btr0sea.c
+++ b/innobase/btr/btr0sea.c
@@ -162,6 +162,8 @@ btr_search_info_create(
 
 	info->last_search = NULL;
 	info->n_direction = 0;
+
+	info->ref_count = 0;
 	info->root_guess = NULL;
 
 	info->hash_analysis = 0;
@@ -183,6 +185,31 @@ btr_search_info_create(
 	return(info);
 }
 
+/*********************************************************************
+Returns the value of ref_count. The value is protected by
+btr_search_latch. */
+ulint
+btr_search_info_get_ref_count(
+/*==========================*/
+				/* out: ref_count value. */
+	btr_search_t*   info)	/* in: search info. */
+{
+	ulint ret;
+
+	ut_ad(info);
+
+#ifdef UNIV_SYNC_DEBUG
+	ut_ad(!rw_lock_own(&btr_search_latch, RW_LOCK_SHARED));
+	ut_ad(!rw_lock_own(&btr_search_latch, RW_LOCK_EX));
+#endif /* UNIV_SYNC_DEBUG */
+
+	rw_lock_s_lock(&btr_search_latch);
+	ret = info->ref_count;
+	rw_lock_s_unlock(&btr_search_latch);
+
+	return(ret);
+}
+
 /*************************************************************************
 Updates the search info of an index about hash successes. NOTE that info
 is NOT protected by any semaphore, to save CPU time! Do not assume its fields
@@ -1019,8 +1046,12 @@ next_rec:
 		ha_remove_all_nodes_to_page(table, folds[i], page);
 	}
 
+	ut_a(index->search_info->ref_count > 0);
+	index->search_info->ref_count--;
+
 	block->is_hashed = FALSE;
 	block->index = NULL;
+	
 cleanup:
 	if (UNIV_UNLIKELY(block->n_pointers)) {
 		/* Corruption */
@@ -1241,6 +1272,15 @@ btr_search_build_page_hash_index(
 		goto exit_func;
 	}
 	
+	/* This counter is decremented every time we drop page
+	hash index entries and is incremented here. Since we can
+	rebuild hash index for a page that is already hashed, we
+	have to take care not to increment the counter in that
+	case. */
+	if (!block->is_hashed) {
+		index->search_info->ref_count++;
+	}
+
 	block->is_hashed = TRUE;
 	block->n_hash_helps = 0;
 	
diff --git a/innobase/dict/dict0dict.c b/innobase/dict/dict0dict.c
index b8d9f362b06..b0d95597153 100644
--- a/innobase/dict/dict0dict.c
+++ b/innobase/dict/dict0dict.c
@@ -1556,6 +1556,8 @@ dict_index_remove_from_cache(
 	dict_field_t*	field;
 	ulint		size;
 	ulint		i;
+	ulint		retries = 0;
+	btr_search_t*	info;
 
 	ut_ad(table && index);
 	ut_ad(table->magic_n == DICT_TABLE_MAGIC_N);
@@ -1564,6 +1566,51 @@ dict_index_remove_from_cache(
 	ut_ad(mutex_own(&(dict_sys->mutex)));
 #endif /* UNIV_SYNC_DEBUG */
 
+	/* We always create search info whether or not adaptive
+	hash index is enabled or not. */
+	info = index->search_info;
+	ut_ad(info);
+
+	/* We are not allowed to free the in-memory index struct
+ 	dict_index_t until all entries in the adaptive hash index
+	that point to any of the page belonging to his b-tree index
+	are dropped. This is so because dropping of these entries
+	require access to dict_index_t struct. To avoid such scenario
+	We keep a count of number of such pages in the search_info and
+	only free the dict_index_t struct when this count drops to
+	zero. */
+
+	for (;;) {
+		ulint ref_count = btr_search_info_get_ref_count(info);
+		if (ref_count == 0) {
+			break;
+		}
+
+		/* Sleep for 10ms before trying again. */
+		os_thread_sleep(10000);
+		++retries;
+
+		if (retries % 500 == 0) {
+			/* No luck after 5 seconds of wait. */
+			fprintf(stderr, "InnoDB: Error: Waited for"
+					" %lu secs for hash index"
+					" ref_count (%lu) to drop"
+					" to 0.\n"
+					"index: \"%s\""
+					" table: \"%s\"\n",
+					retries/100,
+					ref_count,
+					index->name,
+					table->name);
+		}
+
+		/* To avoid a hang here we commit suicide if the
+		ref_count doesn't drop to zero in 600 seconds. */
+		if (retries >= 60000) {
+			ut_error;
+		}
+	}
+
 	ut_ad(UT_LIST_GET_LEN((index->tree)->tree_indexes) == 1);
 	dict_tree_free(index->tree);
 
diff --git a/innobase/include/btr0sea.h b/innobase/include/btr0sea.h
index 78e88a24083..370132af60d 100644
--- a/innobase/include/btr0sea.h
+++ b/innobase/include/btr0sea.h
@@ -40,6 +40,14 @@ btr_search_info_create(
 /*===================*/
 				/* out, own: search info struct */
 	mem_heap_t*	heap);	/* in: heap where created */
+/*********************************************************************
+Returns the value of ref_count. The value is protected by
+btr_search_latch. */
+ulint
+btr_search_info_get_ref_count(
+/*==========================*/
+				/* out: ref_count value. */
+	btr_search_t*   info);	/* in: search info. */
 /*************************************************************************
 Updates the search info. */
 UNIV_INLINE
@@ -144,6 +152,13 @@ btr_search_validate(void);
 
 struct btr_search_struct{
 	ulint	magic_n;	/* magic number */
+	ulint	ref_count;	/* Number of blocks in this index tree
+				that have search index built
+				i.e. block->index points to this index.
+				Protected by btr_search_latch except
+				when during initialization in
+				btr_search_info_create(). */
+
 	/* The following 4 fields are currently not used: */
 	rec_t*	last_search;	/* pointer to the lower limit record of the
 				previous search; NULL if not known */
@@ -154,8 +169,10 @@ struct btr_search_struct{
 				or BTR_SEA_SAME_PAGE */
 	dulint	modify_clock;	/* value of modify clock at the time
 				last_search was stored */
-	/*----------------------*/
-	/* The following 4 fields are not protected by any latch: */
+
+	/* The following fields are not protected by any latch.
+	Unfortunately, this means that they must be aligned to
+	the machine word, i.e., they cannot be turned into bit-fields. */
 	page_t*	root_guess;	/* the root page frame when it was last time
 				fetched, or NULL */
 	ulint	hash_analysis;	/* when this exceeds a certain value, the
diff --git a/innobase/srv/srv0start.c b/innobase/srv/srv0start.c
index 5f8707a661c..d380eb14710 100644
--- a/innobase/srv/srv0start.c
+++ b/innobase/srv/srv0start.c
@@ -180,11 +180,11 @@ srv_parse_data_file_paths_and_sizes(
 		        str++;
 		}
 
-	        if (0 == memcmp(str, ":autoextend", (sizeof ":autoextend") - 1)) {
+		if (0 == strncmp(str, ":autoextend", (sizeof ":autoextend") - 1)) {
 
 			str += (sizeof ":autoextend") - 1;
 
-	        	if (0 == memcmp(str, ":max:", (sizeof ":max:") - 1)) {
+			if (0 == strncmp(str, ":max:", (sizeof ":max:") - 1)) {
 
 				str += (sizeof ":max:") - 1;
 
@@ -288,13 +288,13 @@ srv_parse_data_file_paths_and_sizes(
 		(*data_file_names)[i] = path;
 		(*data_file_sizes)[i] = size;
 
-	        if (0 == memcmp(str, ":autoextend", (sizeof ":autoextend") - 1)) {
+		if (0 == strncmp(str, ":autoextend", (sizeof ":autoextend") - 1)) {
 
 			*is_auto_extending = TRUE;
 
 			str += (sizeof ":autoextend") - 1;
 
-	        	if (0 == memcmp(str, ":max:", (sizeof ":max:") - 1)) {
+			if (0 == strncmp(str, ":max:", (sizeof ":max:") - 1)) {
 
 				str += (sizeof ":max:") - 1;