[glom] Document::add_file_to_archive(): Check the stat() return value.

[Murray Cumming <murrayc src gnome org>]

commit 9c5ff015ffd2dbf1bccf6a6732169b66b3729d32
Author: Murray Cumming <murrayc murrayc com>
Date:   Thu Dec 4 19:43:01 2014 +0100

    Document::add_file_to_archive(): Check the stat() return value.
    
    Found by Coverity Scan.

 glom/libglom/document/document.cc |    7 ++++++-
 1 files changed, 6 insertions(+), 1 deletions(-)
---
diff --git a/glom/libglom/document/document.cc b/glom/libglom/document/document.cc
index 1cb6dcd..116de23 100644
--- a/glom/libglom/document/document.cc
+++ b/glom/libglom/document/document.cc
@@ -4916,7 +4916,12 @@ bool add_file_to_archive(archive* a, const std::string& parent_dir_path, const s
   }
 
   struct stat st;
-  stat(filepath.c_str(), &st);
+  if(stat(filepath.c_str(), &st) < 0)
+  {
+    std::cerr << G_STRFUNC << ": stat() failed." << std::endl;
+    std::cerr << "  : with path: " << filepath << std::endl;
+    return false;
+  }
 
   struct archive_entry* entry = archive_entry_new();
   ScopedArchiveEntryPtr<archive_entry> scoped_entry(entry, &archive_entry_free); //Make sure it is always 
released.