[dia] Bug 729199 - Set xml:space="preserve" to align text starting with spaces

[Hans Breuer <hans src gnome org>]

commit 1bfdbbb7c4b5ef30b7edd580985595e831d279f0
Author: Hans Breuer <hans breuer org>
Date:   Sat Sep 6 15:05:35 2014 +0200

    Bug 729199 - Set xml:space="preserve" to align text starting with spaces
    
    To minimize impact of this deprecated attribute we set it as locally as
    possible and only if it is needed at all. Works for Inkscape, Firefox and
    Chrome but not for IE11.

 plug-ins/svg/render_svg.c |   18 ++++++++++++++++++
 1 files changed, 18 insertions(+), 0 deletions(-)
---
diff --git a/plug-ins/svg/render_svg.c b/plug-ins/svg/render_svg.c
index 1606cdb..efbda1e 100644
--- a/plug-ins/svg/render_svg.c
+++ b/plug-ins/svg/render_svg.c
@@ -417,6 +417,21 @@ node_set_text_style (xmlNodePtr      node,
 }
 
 /*!
+ * To minimize impact of this deprecated attribute we set it as locally as
+ * possible and only if it is needed at all.
+ */
+static void
+_adjust_space_preserve (xmlNodePtr node,
+                       const char *str)
+{
+  gunichar uc;
+  if (!strlen(str))
+    return;
+  uc = g_utf8_get_char_validated (str, -1);
+  if (g_unichar_isspace (uc))
+    xmlSetProp (node, (const xmlChar *)"xml:space", (const xmlChar *)"preserve");
+}
+/*!
  * \brief Support rendering of raw text
  *
  * This is the only function in the renderer interface using the
@@ -435,6 +450,7 @@ draw_string(DiaRenderer *self,
   gchar d_buf[G_ASCII_DTOSTR_BUF_SIZE];
 
   node = xmlNewChild(renderer->root, renderer->svg_name_space, (xmlChar *)"text", (xmlChar *)text);
+  _adjust_space_preserve (node, text);
 
   node_set_text_style(node, renderer, self->font, self->font_height, alignment, colour);
   
@@ -460,6 +476,7 @@ draw_text_line(DiaRenderer *self, TextLine *text_line,
   
   node = xmlNewChild(renderer->root, renderer->svg_name_space, (const xmlChar *)"text", 
                     (xmlChar *) text_line_get_string(text_line));
+  _adjust_space_preserve (node, text_line_get_string(text_line));
 
   /* not using the renderers font but the textlines */
   node_set_text_style(node, renderer, font, font_height, alignment, colour);
@@ -504,6 +521,7 @@ draw_text (DiaRenderer *self, Text *text)
 
     node_tspan = xmlNewTextChild(node_text, renderer->svg_name_space, (const xmlChar *)"tspan",
                                  (const xmlChar *)text_line_get_string(text_line));
+    _adjust_space_preserve (node_tspan, text_line_get_string(text_line));
     dia_svg_dtostr(d_buf, pos.x);
     xmlSetProp(node_tspan, (const xmlChar *)"x", (xmlChar *) d_buf);
     dia_svg_dtostr(d_buf, pos.y);