[gnumeric] Fix border handling for merged cells in LaTeX export.

[Andreas J. Guelzow <guelzow src gnome org>]

commit 03074d492680bf788c0f4b91acff9b283c6485a1
Author: Andreas J Guelzow <aguelzow pyrshep ca>
Date:   Sun Apr 28 16:15:59 2013 -0600

    Fix border handling for merged cells in LaTeX export.
    
    2013-04-28  Andreas J. Guelzow <aguelzow pyrshep ca>
    
        * latex.c (latex2e_find_this_vline): renamed from latex2e_find_vline
        (latex2e_find_vline): new, taking care of merges
        (latex2e_find_hhlines): handle merges

 NEWS                   |    3 ++
 plugins/html/ChangeLog |    6 ++++
 plugins/html/latex.c   |   64 +++++++++++++++++++++++++++++++----------------
 3 files changed, 51 insertions(+), 22 deletions(-)
---
diff --git a/NEWS b/NEWS
index e5fa289..3c2c151 100644
--- a/NEWS
+++ b/NEWS
@@ -1,5 +1,8 @@
 Gnumeric 1.12.3
 
+Andreas:
+       * Fix border handling for merged cells in LaTeX export.
+
 --------------------------------------------------------------------------
 Gnumeric 1.12.2
 
diff --git a/plugins/html/ChangeLog b/plugins/html/ChangeLog
index f7b42eb..1a89d9f 100644
--- a/plugins/html/ChangeLog
+++ b/plugins/html/ChangeLog
@@ -1,3 +1,9 @@
+2013-04-28  Andreas J. Guelzow <aguelzow pyrshep ca>
+
+       * latex.c (latex2e_find_this_vline): renamed from latex2e_find_vline
+       (latex2e_find_vline): new, taking care of merges
+       (latex2e_find_hhlines): handle merges
+
 2013-04-26  Morten Welinder <terra gnome org>
 
        * Release 1.12.2
diff --git a/plugins/html/latex.c b/plugins/html/latex.c
index 64ee72e..f269724 100644
--- a/plugins/html/latex.c
+++ b/plugins/html/latex.c
@@ -700,7 +700,7 @@ latex2e_write_table_header(GsfOutput *output, int num_cols)
  *
  */
 static GnmStyleBorderType
-latex2e_find_vline (int col, int row, Sheet *sheet, GnmStyleElement which_border)
+latex2e_find_this_vline (int col, int row, Sheet *sheet, GnmStyleElement which_border)
 {
        GnmBorder const *border;
        GnmStyle const  *style;
@@ -711,8 +711,7 @@ latex2e_find_vline (int col, int row, Sheet *sheet, GnmStyleElement which_border
        style = sheet_style_get (sheet, col, row);
        border = gnm_style_get_border (style, which_border);
 
-       if (!(gnm_style_border_is_blank (border) ||
-             border->line_type == GNM_STYLE_BORDER_NONE))
+       if (!gnm_style_border_is_blank (border))
                return border->line_type;
 
        if (which_border == MSTYLE_BORDER_LEFT) {
@@ -720,20 +719,43 @@ latex2e_find_vline (int col, int row, Sheet *sheet, GnmStyleElement which_border
                        return GNM_STYLE_BORDER_NONE;
                style = sheet_style_get (sheet, col - 1, row);
                border = gnm_style_get_border (style, MSTYLE_BORDER_RIGHT);
-               return ((gnm_style_border_is_blank (border)) ? GNM_STYLE_BORDER_NONE :
-                       border->line_type);
+               return ((border == NULL) ? GNM_STYLE_BORDER_NONE : border->line_type);
        } else {
                if ((col+1) >= colrow_max (TRUE, sheet))
                    return GNM_STYLE_BORDER_NONE;
                style = sheet_style_get (sheet, col + 1, row);
                border = gnm_style_get_border (style, MSTYLE_BORDER_LEFT);
-               return ((gnm_style_border_is_blank (border)) ? GNM_STYLE_BORDER_NONE :
-                       border->line_type);
+               return ((border == NULL) ? GNM_STYLE_BORDER_NONE : border->line_type);
        }
 
        return GNM_STYLE_BORDER_NONE;
 }
 
+static GnmStyleBorderType
+latex2e_find_vline (int col, int row, Sheet *sheet, GnmStyleElement which_border)
+{
+       /* We are checking for NONE boreders first since there should only be a few merged ranges */
+       GnmStyleBorderType result = latex2e_find_this_vline (col, row, sheet, which_border);
+       GnmCellPos pos;
+       GnmRange const * range;
+
+       if (result == GNM_STYLE_BORDER_NONE)
+               return GNM_STYLE_BORDER_NONE;
+       
+       pos.col = col;
+       pos.row = row;
+       range = gnm_sheet_merge_contains_pos (sheet, &pos);
+
+       if (range) {
+               if ((which_border == MSTYLE_BORDER_LEFT && col == range->start.col)
+                   || (which_border == MSTYLE_BORDER_RIGHT&& col == range->end.col))
+                       return result;
+               else
+                       return GNM_STYLE_BORDER_NONE;   
+       }
+       return result;
+}
+
 /**
  * latex2e_print_vert_border:
  *
@@ -1136,8 +1158,8 @@ latex2e_find_hhlines (GnmStyleBorderType *clines, G_GNUC_UNUSED int length, int
 {
        GnmStyle const  *style;
        GnmBorder const *border;
-       /* GnmRange const       *merge_range; */
-       /* GnmCellPos pos; */
+       GnmRange const  *range;
+       GnmCellPos pos;
 
        style = sheet_style_get (sheet, col, row);
        border = gnm_style_get_border (style, type);
@@ -1145,19 +1167,17 @@ latex2e_find_hhlines (GnmStyleBorderType *clines, G_GNUC_UNUSED int length, int
                return FALSE;
        clines[0] = border->line_type;
 
-       /* The following code completes the border above a merged cell. As long as we allow partial */
-       /* borders above & below merged cells in Gnumeric we should not enable this.                */ 
-       /* pos.col = col; */
-       /* pos.row = row; */
-       /* merge_range = gnm_sheet_merge_is_corner (sheet, &pos); */
-       /* if (merge_range != NULL) { */
-       /*      int i; */
-
-       /*      for (i = 1; i < MIN (merge_range->end.col - merge_range->start.col + 1, */
-       /*                          length); i++) */
-       /*                   clines[i] = border->line_type; */
-       /* } */
-
+       pos.col = col;
+       pos.row = row;
+       range = gnm_sheet_merge_contains_pos (sheet, &pos);
+       if (range) {
+               if ((type == MSTYLE_BORDER_TOP && row > range->start.row)
+                   || (type == MSTYLE_BORDER_BOTTOM&& row < range->end.row)) {
+                       clines[0] = GNM_STYLE_BORDER_NONE;
+                       return FALSE;
+               }
+       }
+       
        return TRUE;
 }