diff --git a/Readme.md b/Readme.md
index fb23a4af97..8e161d36fc 100644
--- a/Readme.md
+++ b/Readme.md
@@ -4,7 +4,7 @@ Libsass
 by Aaron Leung ([@akhleung]) and Hampton Catlin ([@hcatlin])
 
 [![Linux CI](https://travis-ci.org/sass/libsass.png?branch=master)](https://travis-ci.org/sass/libsass)
-[![Windows CI](https://ci.appveyor.com/api/projects/status/s88o0u5qra2ng4vy/branch/master?svg=true)](https://ci.appveyor.com/project/sass/libsass/branch/master)
+[![Windows CI](https://ci.appveyor.com/api/projects/status/github/sass/libsass?svg=true)](https://ci.appveyor.com/project/sass/libsass/branch/master)
 [![Bountysource](https://www.bountysource.com/badge/tracker?tracker_id=283068)](https://www.bountysource.com/trackers/283068-libsass?utm_source=283068&utm_medium=shield&utm_campaign=TRACKER_BADGE)
 [![Coverage Status](https://img.shields.io/coveralls/sass/libsass.svg)](https://coveralls.io/r/sass/libsass?branch=feature%2Ftest-travis-ci-3)
 
diff --git a/appveyor.yml b/appveyor.yml
index acd4d08f96..8f3651c50b 100644
--- a/appveyor.yml
+++ b/appveyor.yml
@@ -20,7 +20,7 @@ cache:
   - C:\Ruby21-x64\bin
 
 install:
-  - git clone https://github.com/mgreter/sassc.git --branch feature/build-dll-win-mingw
+  - git clone https://github.com/sass/sassc.git
   - git clone https://github.com/sass/sass-spec.git
   - set PATH=C:\Ruby%ruby_version%\bin;%PATH%
   - set SASS_LIBSASS_PATH=..
diff --git a/sass_context.cpp b/sass_context.cpp
index aacbdaad60..d538013a5a 100644
--- a/sass_context.cpp
+++ b/sass_context.cpp
@@ -154,6 +154,7 @@ extern "C" {
     void* root;
   };
 
+  static void copy_options(struct Sass_Options* to, struct Sass_Options* from) { *to = *from; }
 
   #define IMPLEMENT_SASS_OPTION_ACCESSOR(type, option) \
     type ADDCALL sass_option_get_##option (struct Sass_Options* options) { return options->option; } \
@@ -498,7 +499,11 @@ extern "C" {
     if (c_ctx->error_status)
       return c_ctx->error_status;
     Context::Data cpp_opt = Context::Data();
-    try { cpp_opt.source_c_str(data_ctx->source_string); }
+    try {
+      if (data_ctx->source_string == 0) { throw(runtime_error("Data context has no source string")); }
+      if (*data_ctx->source_string == 0) { throw(runtime_error("Data context has empty source string")); }
+      cpp_opt.source_c_str(data_ctx->source_string);
+    }
     catch (...) { return handle_errors(c_ctx) || 1; }
     return sass_compile_context(c_ctx, cpp_opt);
   }
@@ -510,7 +515,11 @@ extern "C" {
     if (c_ctx->error_status)
       return c_ctx->error_status;
     Context::Data cpp_opt = Context::Data();
-    try { cpp_opt.entry_point(file_ctx->input_path); }
+    try {
+      if (file_ctx->input_path == 0) { throw(runtime_error("File context has no input path")); }
+      if (*file_ctx->input_path == 0) { throw(runtime_error("File context has empty input path")); }
+      cpp_opt.entry_point(file_ctx->input_path);
+    }
     catch (...) { return handle_errors(c_ctx) || 1; }
     return sass_compile_context(c_ctx, cpp_opt);
   }
@@ -567,7 +576,7 @@ extern "C" {
         ++this_func_data;
       }
     }
-    // Deallocate inc paths
+    // Free custom importer
     if (options->include_paths) {
       struct string_list* cur;
       struct string_list* next;
@@ -643,8 +652,8 @@ extern "C" {
   struct Sass_Options* ADDCALL sass_context_get_options(struct Sass_Context* ctx) { return ctx; }
   struct Sass_Options* ADDCALL sass_file_context_get_options(struct Sass_File_Context* ctx) { return ctx; }
   struct Sass_Options* ADDCALL sass_data_context_get_options(struct Sass_Data_Context* ctx) { return ctx; }
-  void ADDCALL sass_file_context_set_options (struct Sass_File_Context* ctx, struct Sass_Options* opt) { (Sass_Options) *ctx = *opt; }
-  void ADDCALL sass_data_context_set_options (struct Sass_Data_Context* ctx, struct Sass_Options* opt) { (Sass_Options) *ctx = *opt; }
+  void ADDCALL sass_file_context_set_options (struct Sass_File_Context* ctx, struct Sass_Options* opt) { copy_options(ctx, opt); }
+  void ADDCALL sass_data_context_set_options (struct Sass_Data_Context* ctx, struct Sass_Options* opt) { copy_options(ctx, opt); }
 
   // Create getter and setters for options
   IMPLEMENT_SASS_OPTION_ACCESSOR(int, precision);