From 5ca6864a4036ac91c8cb846ae69c876e87a7fd8d Mon Sep 17 00:00:00 2001
From: Seth Hillbrand <hillbrand@ucdavis.edu>
Date: Fri, 4 May 2018 09:10:51 -0700
Subject: [PATCH] Improve error message granularity

When saving a library, check and report on libraries that do not exist
as well as those that exist but are read-only.

Fixes: lp:1769190
* https://bugs.launchpad.net/kicad/+bug/1769190
---
 pcbnew/kicad_plugin.cpp | 16 ++++++++++++----
 1 file changed, 12 insertions(+), 4 deletions(-)

diff --git a/pcbnew/kicad_plugin.cpp b/pcbnew/kicad_plugin.cpp
index 26562a2484..d4f1841946 100644
--- a/pcbnew/kicad_plugin.cpp
+++ b/pcbnew/kicad_plugin.cpp
@@ -126,6 +126,7 @@ public:
 
     wxString    GetPath() const { return m_lib_path.GetPath(); }
     bool        IsWritable() const { return m_lib_path.IsOk() && m_lib_path.IsDirWritable(); }
+    bool        Exists() const { return m_lib_path.IsOk() && m_lib_path.DirExists(); }
     MODULE_MAP& GetModules() { return m_modules; }
 
     // Most all functions in this class throw IO_ERROR exceptions.  There are no
@@ -2070,10 +2071,17 @@ void PCB_IO::FootprintSave( const wxString& aLibraryPath, const MODULE* aFootpri
 
     if( !m_cache->IsWritable() )
     {
-        wxString msg = wxString::Format(
-                _( "Library \"%s\" is read only" ),
-                GetChars( aLibraryPath )
-                );
+        wxString msg;
+        if( !m_cache->Exists() )
+        {
+            msg = wxString::Format( _ ( "Library \"%s\" does not exist" ),
+                    GetChars( aLibraryPath ) );
+        }
+        else
+        {
+            msg = wxString::Format( _( "Library \"%s\" is read only" ),
+                GetChars( aLibraryPath ) );
+        }
 
         THROW_IO_ERROR( msg );
     }