From ac7e2193818abab75879503a496497ea81298748 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Na=C3=AFm=20Favier?= <n@monade.li>
Date: Wed, 7 Jun 2023 18:12:35 +0200
Subject: [PATCH] nix-shell: support single quotes in shebangs

---
 src/nix-build/nix-build.cc | 26 +++++++++++++++++++-------
 tests/shell.shebang.sh     |  2 +-
 2 files changed, 20 insertions(+), 8 deletions(-)

diff --git a/src/nix-build/nix-build.cc b/src/nix-build/nix-build.cc
index 6510df8f041b..2ed080955ccb 100644
--- a/src/nix-build/nix-build.cc
+++ b/src/nix-build/nix-build.cc
@@ -40,7 +40,8 @@ static std::vector<std::string> shellwords(const std::string & s)
     std::string cur;
     enum state {
         sBegin,
-        sQuote
+        sSingleQuote,
+        sDoubleQuote
     };
     state st = sBegin;
     auto it = begin;
@@ -56,15 +57,26 @@ static std::vector<std::string> shellwords(const std::string & s)
             }
         }
         switch (*it) {
+            case '\'':
+                if (st != sDoubleQuote) {
+                    cur.append(begin, it);
+                    begin = it + 1;
+                    st = st == sBegin ? sSingleQuote : sBegin;
+                }
+                break;
             case '"':
-                cur.append(begin, it);
-                begin = it + 1;
-                st = st == sBegin ? sQuote : sBegin;
+                if (st != sSingleQuote) {
+                    cur.append(begin, it);
+                    begin = it + 1;
+                    st = st == sBegin ? sDoubleQuote : sBegin;
+                }
                 break;
             case '\\':
-                /* perl shellwords mostly just treats the next char as part of the string with no special processing */
-                cur.append(begin, it);
-                begin = ++it;
+                if (st != sSingleQuote) {
+                    /* perl shellwords mostly just treats the next char as part of the string with no special processing */
+                    cur.append(begin, it);
+                    begin = ++it;
+                }
                 break;
         }
     }
diff --git a/tests/shell.shebang.sh b/tests/shell.shebang.sh
index f7132043de44..de741e522f1f 100755
--- a/tests/shell.shebang.sh
+++ b/tests/shell.shebang.sh
@@ -1,4 +1,4 @@
 #! @ENV_PROG@ nix-shell
 #! nix-shell -I nixpkgs=shell.nix --no-substitute
-#! nix-shell --pure -i bash -p foo bar
+#! nix-shell --pure -i bash -p '(_: foo) "absurd"' "b\ar"
 echo "$(foo) $(bar) $@"