From 9531a3d8c278c9d2a3a2f6bc2363be3808da5012 Mon Sep 17 00:00:00 2001
From: Lu Wang <coolwanglu@gmail.com>
Date: Sun, 24 Mar 2013 21:42:51 +0800
Subject: [PATCH] fix line merging

---
 src/HTMLRenderer/TextLineBuffer.cc | 47 +++++++++++++++++-------------
 src/HTMLRenderer/state.cc          |  8 ++---
 2 files changed, 30 insertions(+), 25 deletions(-)

diff --git a/src/HTMLRenderer/TextLineBuffer.cc b/src/HTMLRenderer/TextLineBuffer.cc
index a04e1e1..3c52dc0 100644
--- a/src/HTMLRenderer/TextLineBuffer.cc
+++ b/src/HTMLRenderer/TextLineBuffer.cc
@@ -156,36 +156,43 @@ void HTMLRenderer::TextLineBuffer::flush(void)
         if(cur_text_idx >= cur_offset_iter->start_idx)
         {
             double target = cur_offset_iter->width + dx;
+            double actual_offset = 0;
 
-            if(equal(target, 0))
+            if(abs(target) <= renderer->param->h_eps)
             {
-                dx = 0;
-            }
-            else if(equal(target, stack.back()->single_space_offset()))
-            {
-                Unicode u = ' ';
-                outputUnicodes(out, &u, 1);
-                dx = 0;
+                actual_offset = 0;
             }
             else
             {
-                auto & wm = renderer->whitespace_manager;
-                wm.install(target);
-                auto wid = wm.get_id();
-                double w = wm.get_actual_value();
+                double space_off = stack.back()->single_space_offset();
+                if(abs(target - space_off) <= renderer->param->h_eps)
+                {
+                    Unicode u = ' ';
+                    outputUnicodes(out, &u, 1);
+                    actual_offset = space_off;
+                }
+                else
+                {
+                    auto & wm = renderer->whitespace_manager;
+                    wm.install(target);
+                    auto wid = wm.get_id();
+                    actual_offset = wm.get_actual_value();
 
-                if(w < 0)
-                    last_text_pos_with_negative_offset = cur_text_idx;
+                    if(!equal(actual_offset, 0))
+                    {
+                        if(is_positive(-actual_offset))
+                            last_text_pos_with_negative_offset = cur_text_idx;
 
-                auto * p = stack.back();
-                double threshold = p->draw_font_size * (p->font_info->ascent - p->font_info->descent) * (renderer->param->space_threshold);
+                        auto * p = stack.back();
+                        double threshold = p->draw_font_size * (p->font_info->ascent - p->font_info->descent) * (renderer->param->space_threshold);
 
-                out << "<span class=\"" << CSS::WHITESPACE_CN
-                    << ' ' << CSS::WHITESPACE_CN << wid << "\">" << (target > (threshold - EPS) ? " " : "") << "</span>";
+                        out << "<span class=\"" << CSS::WHITESPACE_CN
+                            << ' ' << CSS::WHITESPACE_CN << wid << "\">" << (target > (threshold - EPS) ? " " : "") << "</span>";
 
-                dx = target - w;
+                    }
+                }
             }
-
+            dx = target - actual_offset;
             ++ cur_offset_iter;
         }
 
diff --git a/src/HTMLRenderer/state.cc b/src/HTMLRenderer/state.cc
index 2fff0d1..c4f7e32 100644
--- a/src/HTMLRenderer/state.cc
+++ b/src/HTMLRenderer/state.cc
@@ -271,7 +271,7 @@ void HTMLRenderer::check_state_change(GfxState * state)
 
     // see if the new line is compatible with the current line with proper position shift
     // depends: rise & text position & transformation
-    if(need_recheck_position)
+    if(need_recheck_position && (new_line_state < NLS_DIV))
     {
         // try to transform the old origin under the new TM
         /*
@@ -295,20 +295,18 @@ void HTMLRenderer::check_state_change(GfxState * state)
         if(tm_equal(old_tm, cur_text_tm, 4))
         {
             double lhs1 = cur_text_tm[4] - old_tm[4] - old_tm[2] * (draw_ty - cur_ty) - old_tm[0] * (draw_tx - cur_tx);
-            double lhs2 = cur_text_tm[5] - old_tm[5] - old_tm[3] * (draw_ty - cur_ty) - old_tm[0] * (draw_tx - cur_tx);
+            double lhs2 = cur_text_tm[5] - old_tm[5] - old_tm[3] * (draw_ty - cur_ty) - old_tm[1] * (draw_tx - cur_tx);
 
             if(equal(old_tm[0] * lhs2, old_tm[1] * lhs1))
             {
                 if(!equal(old_tm[0], 0))
                 {
                     dx = lhs1 / old_tm[0];
-                    draw_tx += dx;
                     merged = true;
                 }
                 else if (!equal(old_tm[1], 0))
                 {
                     dx = lhs2 / old_tm[1];
-                    draw_tx += dx;
                     merged = true;
                 }
                 else
@@ -317,7 +315,6 @@ void HTMLRenderer::check_state_change(GfxState * state)
                     {
                         // free
                         dx = 0;
-                        draw_tx = cur_tx;
                         merged = true;
                     }
                     // else fail
@@ -330,6 +327,7 @@ void HTMLRenderer::check_state_change(GfxState * state)
         if(merged)
         {
             text_line_buf->append_offset(dx * draw_text_scale);
+            draw_tx = cur_tx;
             draw_ty = cur_ty;
         }
         else