correctly highlight lines with tabs

highlight_regex.py

@@ -36,11 +36,15 @@ class HighlightRegex(Highlight):
         match_iter = re.finditer(self.regex, line.line())
         for match in match_iter:
             # print("%s" % match)
-            start = match.start(0)
-            end = match.end(0)
+            start_char = match.start(0)
+            end_char = match.end(0)
+
+            start_column = line.char_to_column(start_char)
+            end_column = line.char_to_column(end_char)
+
             result.append(HighlightedRange(
-                start,
-                end - start,
+                start_column,
+                end_column - start_column,
                 highlight_full_line=True,
                 brush=self.brush(self.hit_background_color),
                 brush_full_line=self.brush(self.line_background_color)