From d2390e54c4f1ab5c33a0e35e7b9264b36284fa91 Mon Sep 17 00:00:00 2001
From: Marcel Greter <marcel.greter@ocbnet.ch>
Date: Sun, 3 Nov 2019 00:41:41 +0100
Subject: [PATCH 1/3] Fix nullptr access on interpolated parents

Fixes https://github.com/sass/libsass/issues/3024
---
 src/eval.cpp | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/src/eval.cpp b/src/eval.cpp
index 67f079869..93bce0acc 100644
--- a/src/eval.cpp
+++ b/src/eval.cpp
@@ -690,9 +690,9 @@ namespace Sass {
                                                     b->op(), s_l->last(), b->right());
         bin_ex->is_delayed(b->left()->is_delayed() || b->right()->is_delayed()); // unverified
         for (size_t i = 0; i < s_l->length() - 1; ++i) {
-          ret_schema->append(Cast<PreValue>(s_l->at(i)->perform(this)));
+          ret_schema->append(s_l->at(i)->perform(this));
         }
-        ret_schema->append(Cast<PreValue>(bin_ex->perform(this)));
+        ret_schema->append(bin_ex->perform(this));
         return ret_schema->perform(this);
       }
     }
@@ -703,9 +703,9 @@ namespace Sass {
         Binary_Expression_Obj bin_ex = SASS_MEMORY_NEW(Binary_Expression, b->pstate(),
                                                     b->op(), b->left(), s_r->first());
         bin_ex->is_delayed(b->left()->is_delayed() || b->right()->is_delayed()); // verified
-        ret_schema->append(Cast<PreValue>(bin_ex->perform(this)));
+        ret_schema->append(bin_ex->perform(this));
         for (size_t i = 1; i < s_r->length(); ++i) {
-          ret_schema->append(Cast<PreValue>(s_r->at(i)->perform(this)));
+          ret_schema->append(s_r->at(i)->perform(this));
         }
         return ret_schema->perform(this);
       }

From 994695c669085058c4a500f295a0531893eff77a Mon Sep 17 00:00:00 2001
From: Marcel Greter <marcel.greter@ocbnet.ch>
Date: Sun, 3 Nov 2019 00:42:10 +0100
Subject: [PATCH 2/3] Fix out of boundary vector access

Fixes https://github.com/sass/libsass/issues/3001
---
 src/parser_selectors.cpp | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/src/parser_selectors.cpp b/src/parser_selectors.cpp
index d76dd2ca7..3b4a6e2d9 100644
--- a/src/parser_selectors.cpp
+++ b/src/parser_selectors.cpp
@@ -140,10 +140,12 @@ namespace Sass {
         // parent selector only allowed at start
         // upcoming Sass may allow also trailing
         ParserState state(pstate);
-        SimpleSelectorObj prev = (*seq)[seq->length()-1];
-        std::string sel(prev->to_string({ NESTED, 5 }));
         std::string found("&");
-        if (lex < identifier >()) { found += std::string(lexed); }
+        if (lex < identifier >()) {
+          found += std::string(lexed);
+        }
+        std::string sel(seq->hasRealParent() ? "&" : "");
+        if (!seq->empty()) { sel = seq->last()->to_string({ NESTED, 5 }); }
         // ToDo: parser should throw parser exceptions
         error("Invalid CSS after \"" + sel + "\": expected \"{\", was \"" + found + "\"\n\n"
           "\"" + found + "\" may only be used at the beginning of a compound selector.", state);

From 0b721e0f37fc69ab197ec956a923e036e3b05ca6 Mon Sep 17 00:00:00 2001
From: Marcel Greter <marcel.greter@ocbnet.ch>
Date: Sun, 3 Nov 2019 01:06:18 +0100
Subject: [PATCH 3/3] Fix out of boundary vector access

Fixes https://github.com/sass/libsass/issues/2999
---
 src/ast_sel_weave.cpp | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/src/ast_sel_weave.cpp b/src/ast_sel_weave.cpp
index 2785ea370..c792d0f8a 100644
--- a/src/ast_sel_weave.cpp
+++ b/src/ast_sel_weave.cpp
@@ -576,8 +576,12 @@ namespace Sass {
       // Prepare data structures
       choices.push_back(expanded);
       choices.push_back({ group });
-      groups1.erase(groups1.begin());
-      groups2.erase(groups2.begin());
+      if (!groups1.empty()) {
+        groups1.erase(groups1.begin());
+      }
+      if (!groups2.empty()) {
+        groups2.erase(groups2.begin());
+      }
 
     }