diff --git a/src/HTMLRenderer/font.cc b/src/HTMLRenderer/font.cc
index f13fac6..7665748 100644
--- a/src/HTMLRenderer/font.cc
+++ b/src/HTMLRenderer/font.cc
@@ -346,12 +346,13 @@ void HTMLRenderer::embed_font(const string & filepath, GfxFont * font, FontInfo
 
 
     {
+        string map_filename;
         ofstream map_outf;
         if(param.debug)
         {
-            string fn = (char*)str_fmt("%s/f%llx.map", param.tmp_dir.c_str(), info.id);
-            tmp_files.add(fn);
-            map_outf.open(fn);
+            map_filename = (char*)str_fmt("%s/f%llx.map", param.tmp_dir.c_str(), info.id);
+            tmp_files.add(map_filename);
+            map_outf.open(map_filename);
         }
 
         unordered_set<int> codeset;
@@ -427,7 +428,8 @@ void HTMLRenderer::embed_font(const string & filepath, GfxFont * font, FontInfo
                         cur_code = -1;
                         if(param.debug)
                         {
-                            map_outf.seekp(0);
+                            map_outf.close();
+                            map_outf.open(map_filename);
                         }
                         continue;
                     }
diff --git a/src/HTMLRenderer/general.cc b/src/HTMLRenderer/general.cc
index daafcea..dc7ae3a 100644
--- a/src/HTMLRenderer/general.cc
+++ b/src/HTMLRenderer/general.cc
@@ -396,9 +396,23 @@ void HTMLRenderer::post_process(void)
             continue;
         }
 
-        if(line.empty() 
-           || (line.find_first_not_of(' ') == string::npos)
-           || line[0] == '#')
+        // trim space at both sides
+        {
+            static const char * whitespaces = " \t\n\v\f\r";
+            auto idx1 = line.find_first_not_of(whitespaces);
+            if(idx1 == string::npos)
+            {
+                line.clear();
+            }
+            else
+            {
+                auto idx2 = line.find_last_not_of(whitespaces);
+                assert(idx2 >= idx1);
+                line = line.substr(idx1, idx2 - idx1 + 1);
+            }
+        }
+
+        if(line.empty() || line[0] == '#')
             continue;