1 files changed, 50 insertions, 2 deletions

diff --git a/erts/emulator/beam/erl_bits.c b/erts/emulator/beam/erl_bits.c
index 3a16913473..f5807d25d7 100644
--- a/erts/emulator/beam/erl_bits.c
+++ b/erts/emulator/beam/erl_bits.c
@@ -144,6 +144,42 @@ erts_bs_start_match_2(Process *p, Eterm Binary, Uint Max)
     return make_matchstate(ms);
 }
 
+ErlBinMatchState *erts_bs_start_match_3(Process *p, Eterm Binary)
+{
+    Eterm Orig;
+    Uint offs;
+    Uint* hp;
+    Uint NeededSize;
+    ErlBinMatchState *ms;
+    Uint bitoffs;
+    Uint bitsize;
+    Uint total_bin_size;
+    ProcBin* pb;
+
+    ASSERT(is_binary(Binary));
+    total_bin_size = binary_size(Binary);
+    if ((total_bin_size >> (8*sizeof(Uint)-3)) != 0) {
+        return NULL;
+    }
+
+    NeededSize = ERL_BIN_MATCHSTATE_SIZE(0);
+    hp = HeapOnlyAlloc(p, NeededSize);
+    ms = (ErlBinMatchState *) hp;
+    ERTS_GET_REAL_BIN(Binary, Orig, offs, bitoffs, bitsize);
+    pb = (ProcBin *) boxed_val(Orig);
+    if (pb->thing_word == HEADER_PROC_BIN && pb->flags != 0) {
+        erts_emasculate_writable_binary(pb);
+    }
+
+    ms->thing_word = HEADER_BIN_MATCHSTATE(0);
+    (ms->mb).orig = Orig;
+    (ms->mb).base = binary_bytes(Orig);
+    (ms->mb).offset = 8 * offs + bitoffs;
+    (ms->mb).size = total_bin_size * 8 + (ms->mb).offset + bitsize;
+
+    return ms;
+}
+
 #ifdef DEBUG
 # define CHECK_MATCH_BUFFER(MB) check_match_buffer(MB)
 
@@ -1295,6 +1331,14 @@ erts_bs_append(Process* c_p, Eterm* reg, Uint live, Eterm build_size_term,
 	}
     }
 
+    if (build_size_in_bits == 0) {
+        if (c_p->stop - c_p->htop < extra_words) {
+            (void) erts_garbage_collect(c_p, extra_words, reg, live+1);
+            bin = reg[live];
+        }
+	return bin;
+    }
+
     if((ERTS_UINT_MAX - build_size_in_bits) < erts_bin_offset) {
         c_p->freason = SYSTEM_LIMIT;
         return THE_NON_VALUE;
@@ -1352,13 +1396,13 @@ erts_bs_append(Process* c_p, Eterm* reg, Uint live, Eterm build_size_term,
 	Uint bitsize;
 	Eterm* hp;
 
-	/*
+        /*
 	 * Allocate heap space.
 	 */
 	heap_need = PROC_BIN_SIZE + ERL_SUB_BIN_SIZE + extra_words;
 	if (c_p->stop - c_p->htop < heap_need) {
 	    (void) erts_garbage_collect(c_p, heap_need, reg, live+1);
-	    bin = reg[live];
+            bin = reg[live];
 	}
 	hp = c_p->htop;
 
@@ -1376,6 +1420,10 @@ erts_bs_append(Process* c_p, Eterm* reg, Uint live, Eterm build_size_term,
 	    }
 	}
 
+	if (build_size_in_bits == 0) {
+            return bin;
+	}
+
         if((ERTS_UINT_MAX - build_size_in_bits) < erts_bin_offset) {
             c_p->freason = SYSTEM_LIMIT;
             return THE_NON_VALUE;