Correctly compute line numbers in functions from the function constructor.

src/objects.cc

Index: src/objects.cc
diff --git a/src/objects.cc b/src/objects.cc
index 01b4a1aca09f61e9504b67a41f7f6abb66971e39..13952e838b0d6637c047000ae02872ee8da5d214 100644
--- a/src/objects.cc
+++ b/src/objects.cc
@@ -9932,27 +9932,31 @@ int Script::GetColumnNumber(Handle<Script> script, int code_pos) {
 }
 
 
-int Script::GetLineNumberWithArray(int code_pos) {
+int Script::GetLineNumberWithArray(int position) {
   DisallowHeapAllocation no_allocation;
-  DCHECK(line_ends()->IsFixedArray());
-  FixedArray* line_ends_array = FixedArray::cast(line_ends());
-  int line_ends_len = line_ends_array->length();
-  if (line_ends_len == 0) return -1;
+  FixedArray* line_ends = FixedArray::cast(this->line_ends());
+  int upper = line_ends->length() - 1;
+  if (upper < 0) return -1;
+  int offset = line_offset()->value();
 
-  if ((Smi::cast(line_ends_array->get(0)))->value() >= code_pos) {
-    return line_offset()->value();
+  if (position > Smi::cast(line_ends->get(upper))->value()) {
+    return upper + 1 + offset;
   }
+  if (position <= Smi::cast(line_ends->get(0))->value()) return offset;
 
-  int left = 0;
-  int right = line_ends_len;
-  while (int half = (right - left) / 2) {
-    if ((Smi::cast(line_ends_array->get(left + half)))->value() > code_pos) {
-      right -= half;
+  int lower = 1;
+  // Binary search.
+  while (true) {
+    int mid = (lower + upper) / 2;
+    if (position <= Smi::cast(line_ends->get(mid - 1))->value()) {
+      upper = mid - 1;
+    } else if (position > Smi::cast(line_ends->get(mid))->value()) {
+      lower = mid + 1;
     } else {
-      left += half;
+      return mid + offset;
     }
   }
-  return right + line_offset()->value();
+  return -1;
 }