community/libsass: fix some cases of "extend" causing an endless loop

breeze-gtk encountered this and had to be prevented from upgrading
because of it

3 files changed, 165 insertions, 3 deletions

diff --git a/community/libsass/APKBUILD b/community/libsass/APKBUILD
index 1f71fbd515..d98e95948d 100644
--- a/community/libsass/APKBUILD
+++ b/community/libsass/APKBUILD
@@ -2,7 +2,7 @@
 # Contributor: Thomas Boerger <thomas@webhippie.de>
 pkgname=libsass
 pkgver=3.6.2
-pkgrel=0
+pkgrel=1
 pkgdesc="C/C++ implementation of a Sass compiler"
 options="!check" # No tests are run when make check is run
 url="https://sass-lang.com/libsass"
@@ -10,7 +10,9 @@ arch="all"
 license="MIT"
 makedepends="autoconf automake libtool"
 subpackages="$pkgname-dev"
-source="$pkgname-$pkgver.tar.gz::https://github.com/sass/libsass/archive/$pkgver.tar.gz"
+source="$pkgname-$pkgver.tar.gz::https://github.com/sass/libsass/archive/$pkgver.tar.gz
+	fix-extend-issue-being-stuck-in-endless-loop.patch
+	fix-trim-loop-condition-and-outer-continue.patch"
 
 prepare() {
 	default_prepare
@@ -31,4 +33,6 @@ package() {
 	rm -f "$pkgdir"/usr/lib/*.la
 }
 
-sha512sums="b1ee92de64f4eeabe2d4bfc693349ac124a81115554228669526e863d18f3c67ab44698414cf204f545eb4a4126ca350a1c7f7658e9ebac447f8b2e7533d9772  libsass-3.6.2.tar.gz"
+sha512sums="b1ee92de64f4eeabe2d4bfc693349ac124a81115554228669526e863d18f3c67ab44698414cf204f545eb4a4126ca350a1c7f7658e9ebac447f8b2e7533d9772  libsass-3.6.2.tar.gz
+e4684766f05cabe7ed360b7c1b0ed282d7f19223c3667e10b4a204492fadf21ed91289f9876ae7fa30c124c3edd73e117418329a2dd30b4d830657dba1193008  fix-extend-issue-being-stuck-in-endless-loop.patch
+f2fe27d12cf9250024481e6de3a532a64d1d08931c34138a05411bfefc44937a1917e4fc61aa33cbb5e92d369baed3ae46b7d2a4905be1aad1294021c6c07e26  fix-trim-loop-condition-and-outer-continue.patch"
diff --git a/community/libsass/fix-extend-issue-being-stuck-in-endless-loop.patch b/community/libsass/fix-extend-issue-being-stuck-in-endless-loop.patch
new file mode 100644
index 0000000000..6ade4efdc9
--- /dev/null
+++ b/community/libsass/fix-extend-issue-being-stuck-in-endless-loop.patch
@@ -0,0 +1,122 @@
+From 1ec3876afc071a79bb2d104b0b79306392e20bc4 Mon Sep 17 00:00:00 2001
+From: Marcel Greter <marcel.greter@ocbnet.ch>
+Date: Fri, 18 Oct 2019 07:22:52 +0200
+Subject: [PATCH] Fix extend issue being stuck in endless loop
+
+Fixes https://github.com/sass/libsass/issues/3006
+---
+ src/eval_selectors.cpp |  6 +++---
+ src/expand.cpp         | 29 +++++++++++++++++++++++------
+ src/expand.hpp         |  3 +++
+ src/extender.hpp       |  4 ++--
+ 4 files changed, 31 insertions(+), 11 deletions(-)
+
+diff --git a/src/eval_selectors.cpp b/src/eval_selectors.cpp
+index cc7d3409c..db797e5bd 100644
+--- a/src/eval_selectors.cpp
++++ b/src/eval_selectors.cpp
+@@ -46,10 +46,10 @@ namespace Sass {
+   SelectorList* Eval::operator()(ComplexSelector* s)
+   {
+     bool implicit_parent = !exp.old_at_root_without_rule;
+-    if (is_in_selector_schema) exp.pushToSelectorStack({});
++    if (is_in_selector_schema) exp.pushNullSelector();
+     SelectorListObj other = s->resolve_parent_refs(
+-      exp.getSelectorStack(), traces, implicit_parent);
+-    if (is_in_selector_schema) exp.popFromSelectorStack();
++      exp.getOriginalStack(), traces, implicit_parent);
++    if (is_in_selector_schema) exp.popNullSelector();
+ 
+     for (size_t i = 0; i < other->length(); i++) {
+       ComplexSelectorObj sel = other->at(i);
+diff --git a/src/expand.cpp b/src/expand.cpp
+index 1b9bf9158..0380e1cec 100644
+--- a/src/expand.cpp
++++ b/src/expand.cpp
+@@ -62,6 +62,23 @@ namespace Sass {
+     return 0;
+   }
+ 
++  void Expand::pushNullSelector()
++  {
++    pushToSelectorStack({});
++    pushToOriginalStack({});
++  }
++
++  void Expand::popNullSelector()
++  {
++    popFromOriginalStack();
++    popFromSelectorStack();
++  }
++
++  SelectorStack Expand::getOriginalStack()
++  {
++    return originalStack;
++  }
++
+   SelectorStack Expand::getSelectorStack()
+   {
+     return selector_stack;
+@@ -153,15 +170,15 @@ namespace Sass {
+       Block* bb = operator()(r->block());
+       Keyframe_Rule_Obj k = SASS_MEMORY_NEW(Keyframe_Rule, r->pstate(), bb);
+       if (r->schema()) {
+-        pushToSelectorStack({});
++        pushNullSelector();
+         k->name(eval(r->schema()));
+-        popFromSelectorStack();
++        popNullSelector();
+       }
+       else if (r->selector()) {
+         if (SelectorListObj s = r->selector()) {
+-          pushToSelectorStack({});
++          pushNullSelector();
+           k->name(eval(s));
+-          popFromSelectorStack();
++          popNullSelector();
+         }
+       }
+ 
+@@ -288,10 +305,10 @@ namespace Sass {
+     Block* ab = a->block();
+     SelectorList* as = a->selector();
+     Expression* av = a->value();
+-    pushToSelectorStack({});
++    pushNullSelector();
+     if (av) av = av->perform(&eval);
+     if (as) as = eval(as);
+-    popFromSelectorStack();
++    popNullSelector();
+     Block* bb = ab ? operator()(ab) : NULL;
+     Directive* aa = SASS_MEMORY_NEW(Directive,
+                                   a->pstate(),
+diff --git a/src/expand.hpp b/src/expand.hpp
+index db5852ce4..90edbf4ca 100644
+--- a/src/expand.hpp
++++ b/src/expand.hpp
+@@ -22,7 +22,10 @@ namespace Sass {
+     SelectorListObj& selector();
+     SelectorListObj& original();
+     SelectorListObj popFromSelectorStack();
++    SelectorStack getOriginalStack();
+     SelectorStack getSelectorStack();
++    void pushNullSelector();
++    void popNullSelector();
+     void pushToSelectorStack(SelectorListObj selector);
+ 
+     SelectorListObj popFromOriginalStack();
+diff --git a/src/extender.hpp b/src/extender.hpp
+index 4b00cc3a0..5f161786a 100644
+--- a/src/extender.hpp
++++ b/src/extender.hpp
+@@ -126,8 +126,8 @@ namespace Sass {
+     std::unordered_map<
+       SimpleSelectorObj,
+       size_t,
+-      ObjHash,
+-      ObjEquality
++      ObjPtrHash,
++      ObjPtrEquality
+     > sourceSpecificity;
+ 
+     // ##########################################################################
diff --git a/community/libsass/fix-trim-loop-condition-and-outer-continue.patch b/community/libsass/fix-trim-loop-condition-and-outer-continue.patch
new file mode 100644
index 0000000000..b1c2acf455
--- /dev/null
+++ b/community/libsass/fix-trim-loop-condition-and-outer-continue.patch
@@ -0,0 +1,36 @@
+From fdf63e4c93d40c1c4da43fdf13010d590dc133e0 Mon Sep 17 00:00:00 2001
+From: Marcel Greter <marcel.greter@ocbnet.ch>
+Date: Sun, 20 Oct 2019 04:45:29 +0200
+Subject: [PATCH] Fix trim loop condition and outer continue
+
+---
+ src/extender.cpp | 8 ++++----
+ 1 file changed, 4 insertions(+), 4 deletions(-)
+
+diff --git a/src/extender.cpp b/src/extender.cpp
+index 2ae54df98..b0add3857 100644
+--- a/src/extender.cpp
++++ b/src/extender.cpp
+@@ -1070,10 +1070,10 @@ namespace Sass {
+     // the result so that, if two selectors are identical, we keep the first one.
+     std::vector<ComplexSelectorObj> result; size_t numOriginals = 0;
+ 
+-    // Use label to quit outer loop
+-  redo:
++    size_t i = selectors.size();
++  outer: // Use label to continue loop
++    while (--i != std::string::npos) {
+ 
+-    for (size_t i = selectors.size() - 1; i != std::string::npos; i--) {
+       const ComplexSelectorObj& complex1 = selectors[i];
+       // Check if selector in known in existing "originals"
+       // For custom behavior dart-sass had `isOriginal(complex1)`
+@@ -1083,7 +1083,7 @@ namespace Sass {
+         for (size_t j = 0; j < numOriginals; j++) {
+           if (ObjEqualityFn(result[j], complex1)) {
+             rotateSlice(result, 0, j + 1);
+-            goto redo;
++            goto outer;
+           }
+         }
+         result.insert(result.begin(), complex1);