From d09ec9ee97816bd987e6322797b0e28c27f8590a Mon Sep 17 00:00:00 2001
From: Sverker Eriksson <sverker@erlang.org>
Date: Wed, 25 Mar 2015 20:50:12 +0100
Subject: erts: Fix bug in term_to_binary size estimation for hamt

---
 erts/emulator/beam/external.c | 39 +++++++++++++++++++++++++++++++++++----
 1 file changed, 35 insertions(+), 4 deletions(-)

(limited to 'erts/emulator/beam/external.c')

diff --git a/erts/emulator/beam/external.c b/erts/emulator/beam/external.c
index 4cd57d8aeb..8f0e19d27d 100644
--- a/erts/emulator/beam/external.c
+++ b/erts/emulator/beam/external.c
@@ -4172,8 +4172,12 @@ encode_size_struct_int(TTBSizeContext* ctx, ErtsAtomCacheMap *acmp, Eterm obj,
 		case HAMT_SUBTAG_HEAD_ARRAY:
 		    ptr++;
 		    node_sz = 16;
+		    result += 1 + 4; /* tag + 4 bytes size */
 		    break;
-		case HAMT_SUBTAG_HEAD_BITMAP: ptr++;
+		case HAMT_SUBTAG_HEAD_BITMAP:
+		    ptr++;
+		    result += 1 + 4; /* tag + 4 bytes size */
+		    /*fall through*/
 		case HAMT_SUBTAG_NODE_BITMAP:
 		    node_sz = hashmap_bitcount(MAP_HEADER_VAL(hdr));
 		    ASSERT(node_sz < 17);
@@ -4183,11 +4187,38 @@ encode_size_struct_int(TTBSizeContext* ctx, ErtsAtomCacheMap *acmp, Eterm obj,
 		}
 
 		ptr++;
-		ESTACK_RESERVE(s, node_sz);
+		ESTACK_RESERVE(s, node_sz*2);
 		while(node_sz--) {
-		    ESTACK_FAST_PUSH(s, *ptr++);
+                    if (is_list(*ptr)) {
+			Eterm* leaf = list_val(*ptr);
+			if (is_not_list(CAR(leaf))) {
+			    ESTACK_FAST_PUSH(s, CAR(leaf));
+			}
+			else {
+			    if ((m = is_string(CAR(leaf))) && (m < MAX_STRING_LEN)) {
+				result += m + 2 + 1;
+			    } else {
+				result += 5;
+				ESTACK_FAST_PUSH(s, CAR(leaf));
+			    }
+			}
+			if (is_not_list(CDR(leaf))) {
+			    ESTACK_FAST_PUSH(s, CDR(leaf));
+			}
+			else {
+			    if ((m = is_string(CDR(leaf))) && (m < MAX_STRING_LEN)) {
+				result += m + 2 + 1;
+			    } else {
+				result += 5;
+				ESTACK_FAST_PUSH(s, CDR(leaf));
+			    }
+			}
+		    }
+		    else {
+			ESTACK_FAST_PUSH(s, *ptr);
+		    }
+		    ptr++;
 		}
-		result += 1 + 4; /* tag + 4 bytes size */
 	    }
 
 	    break;
-- 
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