[wasm] Fix importing wasm functions which are being debugged

src/inspector/wasm-translation.cc

 // Copyright 2016 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/inspector/wasm-translation.h"
 
 #include <algorithm>
 
 #include "src/debug/debug-interface.h"
 #include "src/inspector/protocol/Debugger.h"
@@ skipping 105 matching lines @@
       auto& entry = (*reverse_table)[mid];
       if (entry.line < loc->line ||
           (entry.line == loc->line && entry.column <= loc->column)) {
         left = mid;
       } else {
         right = mid;
       }
     }
 
     int found_byte_offset = 0;
-    // If we found an exact match, use it. Otherwise check whether the next
-    // bigger entry is still in the same line. Report that one then.
-    // Otherwise we might have hit the special case of pointing after the last
-    // line, which is translated to the end of the function (one byte after the
-    // last function byte).
+    // [left] is <= <line,column>, or left==0 and [0] > <line,column>.
+    // We are searching for the smallest entry >= <line,column> which is still
+    // on the same line. This must be either [left] or [left + 1].
+    // If we don't find such an entry, we might have hit the special case of
+    // pointing after the last line, which is translated to the end of the
+    // function (one byte after the last function byte).
     if ((*reverse_table)[left].line == loc->line &&
-        (*reverse_table)[left].column == loc->column) {
+        (*reverse_table)[left].column >= loc->column) {
       found_byte_offset = (*reverse_table)[left].byte_offset;
     } else if (left + 1 < reverse_table->size() &&
-               (*reverse_table)[left + 1].line == loc->line) {
+               (*reverse_table)[left + 1].line == loc->line &&
+               (*reverse_table)[left + 1].column >= loc->column) {
       found_byte_offset = (*reverse_table)[left + 1].byte_offset;
     } else if (left == reverse_table->size() - 1 &&
                (*reverse_table)[left].line == loc->line - 1 &&
                loc->column == 0) {
       std::pair<int, int> func_range =
           script_.Get(isolate)->GetFunctionRange(func_index);
       DCHECK_LE(func_range.first, func_range.second);
       found_byte_offset = func_range.second - func_range.first;
     }
 
@@ skipping 172 matching lines @@
   *column_number = trans_loc.column;
 
   return true;
 }
 
 void WasmTranslation::AddFakeScript(const String16& scriptId,
                                     TranslatorImpl* translator) {
   DCHECK_EQ(0, fake_scripts_.count(scriptId));
   fake_scripts_.insert(std::make_pair(scriptId, translator));
 }