From 9d07a48cedf58906f5c344152b591f9485146610 Mon Sep 17 00:00:00 2001
From: Marcel Greter <marcel.greter@ocbnet.ch>
Date: Sat, 7 Mar 2015 03:12:07 +0100
Subject: [PATCH] Add improvements to interpolate parsing

---
 parser.cpp   | 12 ++++++------
 prelexer.cpp |  4 ++--
 prelexer.hpp | 19 ++++++++++++++++---
 util.cpp     |  5 ++++-
 4 files changed, 28 insertions(+), 12 deletions(-)

diff --git a/parser.cpp b/parser.cpp
index f0ed5c5767..a736557586 100644
--- a/parser.cpp
+++ b/parser.cpp
@@ -1273,7 +1273,7 @@ namespace Sass {
   {
     const char* i = chunk.begin;
     // see if there any interpolants
-    const char* p = find_first_in_interval< sequence< negate< exactly<'\\'> >, exactly<hash_lbrace> > >(i, chunk.end);
+    const char* p = find_first_in_interval< exactly<hash_lbrace> >(i, chunk.end);
     if (!p) {
       String_Quoted* str_quoted = new (ctx.mem) String_Quoted(pstate, string(i, chunk.end));
       if (!constant && str_quoted->quote_mark()) str_quoted->quote_mark('*');
@@ -1283,7 +1283,7 @@ namespace Sass {
 
     String_Schema* schema = new (ctx.mem) String_Schema(pstate);
     while (i < chunk.end) {
-      p = find_first_in_interval< sequence< negate< exactly<'\\'> >, exactly<hash_lbrace> > >(i, chunk.end);
+      p = find_first_in_interval< exactly<hash_lbrace> >(i, chunk.end);
       if (p) {
         if (i < p) {
           // accumulate the preceding segment if it's nonempty
@@ -1338,7 +1338,7 @@ namespace Sass {
     Token str(lexed);
     const char* i = str.begin;
     // see if there any interpolants
-    const char* p = find_first_in_interval< sequence< negate< exactly<'\\'> >, exactly<hash_lbrace> > >(str.begin, str.end);
+    const char* p = find_first_in_interval< exactly<hash_lbrace> >(str.begin, str.end);
     if (!p) {
       String_Constant* str_node = new (ctx.mem) String_Constant(pstate, normalize_wspace(string(str.begin, str.end)));
       str_node->is_delayed(true);
@@ -1347,7 +1347,7 @@ namespace Sass {
 
     String_Schema* schema = new (ctx.mem) String_Schema(pstate);
     while (i < str.end) {
-      p = find_first_in_interval< sequence< negate< exactly<'\\'> >, exactly<hash_lbrace> > >(i, str.end);
+      p = find_first_in_interval< exactly<hash_lbrace> >(i, str.end);
       if (p) {
         if (i < p) {
           (*schema) << new (ctx.mem) String_Constant(pstate, string(i, p)); // accumulate the preceding segment if it's nonempty
@@ -1474,14 +1474,14 @@ namespace Sass {
     Token id(lexed);
     const char* i = id.begin;
     // see if there any interpolants
-    const char* p = find_first_in_interval< sequence< negate< exactly<'\\'> >, exactly<hash_lbrace> > >(id.begin, id.end);
+    const char* p = find_first_in_interval< exactly<hash_lbrace> >(id.begin, id.end);
     if (!p) {
       return new (ctx.mem) String_Quoted(pstate, string(id.begin, id.end));
     }
 
     String_Schema* schema = new (ctx.mem) String_Schema(pstate);
     while (i < id.end) {
-      p = find_first_in_interval< sequence< negate< exactly<'\\'> >, exactly<hash_lbrace> > >(i, id.end);
+      p = find_first_in_interval< exactly<hash_lbrace> >(i, id.end);
       if (p) {
         if (i < p) {
           // accumulate the preceding segment if it's nonempty
diff --git a/prelexer.cpp b/prelexer.cpp
index f3de77f3e7..a3a7a3e541 100644
--- a/prelexer.cpp
+++ b/prelexer.cpp
@@ -167,7 +167,7 @@ namespace Sass {
         zero_plus <
           alternatives <
             // skip all escaped chars first
-            sequence < exactly < '\\' >, any_char >,
+            backslash_something,
             // skip interpolants
             interpolant,
             // skip non delimiters
@@ -186,7 +186,7 @@ namespace Sass {
         zero_plus <
           alternatives <
             // skip all escaped chars first
-            sequence < exactly < '\\' >, any_char >,
+            backslash_something,
             // skip interpolants
             interpolant,
             // skip non delimiters
diff --git a/prelexer.hpp b/prelexer.hpp
index e0950b5061..fa4953481a 100644
--- a/prelexer.hpp
+++ b/prelexer.hpp
@@ -565,8 +565,11 @@ namespace Sass {
     }
     template<prelexer mx>
     const char* find_first_in_interval(const char* beg, const char* end) {
+      bool esc = false;
       while ((beg < end) && *beg) {
-        if (mx(beg)) return beg;
+        if (esc) esc = false;
+        else if (*beg == '\\') esc = true;
+        else if (mx(beg)) return beg;
         ++beg;
       }
       return 0;
@@ -574,8 +577,11 @@ namespace Sass {
     template <char c>
     unsigned int count_interval(const char* beg, const char* end) {
       unsigned int counter = 0;
+      bool esc = false;
       while (beg < end && *beg) {
-        if (*beg == c) ++counter;
+        if (esc) esc = false;
+        else if (*beg == '\\') esc = true;
+        else if (*beg == c) ++counter;
         ++beg;
       }
       return counter;
@@ -583,9 +589,16 @@ namespace Sass {
     template <prelexer mx>
     unsigned int count_interval(const char* beg, const char* end) {
       unsigned int counter = 0;
+      bool esc = false;
       while (beg < end && *beg) {
         const char* p;
-        if ((p = mx(beg))) {
+        if (esc) {
+          esc = false;
+          ++beg;
+        } else if (*beg == '\\') {
+          esc = true;
+          ++beg;
+        } else if ((p = mx(beg))) {
           ++counter;
           beg = p;
         }
diff --git a/util.cpp b/util.cpp
index 64feda300e..f6a89db71b 100644
--- a/util.cpp
+++ b/util.cpp
@@ -106,7 +106,10 @@ namespace Sass {
         out += i;
       }
     }
-    if (esc) out += 'Z';
+    // happens when parsing does not correctly skip
+    // over escaped sequences for ie. interpolations
+    // one example: foo\#{interpolate}
+    // if (esc) out += '\\';
     return out;
   }