[latexila] PostProcessorLatex: fix critical message

[Sébastien Wilmet <swilmet src gnome org>]

commit 9be0238086c8511dcce558e08293e731cae30e73
Author: Sébastien Wilmet <swilmet gnome org>
Date:   Mon Oct 6 21:32:04 2014 +0200

    PostProcessorLatex: fix critical message

 src/liblatexila/latexila-post-processor-latex.c |   12 +++++++++---
 1 files changed, 9 insertions(+), 3 deletions(-)
---
diff --git a/src/liblatexila/latexila-post-processor-latex.c b/src/liblatexila/latexila-post-processor-latex.c
index 72876e2..c786909 100644
--- a/src/liblatexila/latexila-post-processor-latex.c
+++ b/src/liblatexila/latexila-post-processor-latex.c
@@ -154,9 +154,15 @@ static void
 append_to_line_buffer (LatexilaPostProcessorLatex *pp,
                        const gchar                *line)
 {
-  g_return_if_fail (pp->priv->line_buffer != NULL);
-  g_string_append (pp->priv->line_buffer, line);
-  pp->priv->lines_count++;
+  if (pp->priv->line_buffer == NULL)
+    {
+      set_line_buffer (pp, line);
+    }
+  else
+    {
+      g_string_append (pp->priv->line_buffer, line);
+      pp->priv->lines_count++;
+    }
 }
 
 static void