From d0896d641ad1d27c2d3396087f3c27076027d116 Mon Sep 17 00:00:00 2001
From: Bo Anderson <mail@boanderson.me>
Date: Thu, 5 Mar 2020 03:40:23 +0000
Subject: [PATCH] extend/string: match multiline make variables

---
 Library/Homebrew/extend/string.rb       |  6 +--
 Library/Homebrew/test/inreplace_spec.rb | 49 +++++++++++++++++++++++++
 2 files changed, 52 insertions(+), 3 deletions(-)

diff --git a/Library/Homebrew/extend/string.rb b/Library/Homebrew/extend/string.rb
index fae54878e4..a0dcb38776 100644
--- a/Library/Homebrew/extend/string.rb
+++ b/Library/Homebrew/extend/string.rb
@@ -41,7 +41,7 @@ module StringInreplaceExtension
   # Looks for Makefile style variable definitions and replaces the
   # value with "new_value", or removes the definition entirely.
   def change_make_var!(flag, new_value)
-    return if gsub!(/^#{Regexp.escape(flag)}[ \t]*[\\?\+\:\!]?=[ \t]*(.*)$/, "#{flag}=#{new_value}", false)
+    return if gsub!(/^#{Regexp.escape(flag)}[ \t]*[\\?\+\:\!]?=[ \t]*((?:.*\\\n)*.*)$/, "#{flag}=#{new_value}", false)
 
     errors << "expected to change #{flag.inspect} to #{new_value.inspect}"
   end
@@ -50,7 +50,7 @@ module StringInreplaceExtension
   def remove_make_var!(flags)
     Array(flags).each do |flag|
       # Also remove trailing \n, if present.
-      unless gsub!(/^#{Regexp.escape(flag)}[ \t]*[\\?\+\:\!]?=.*$\n?/, "", false)
+      unless gsub!(/^#{Regexp.escape(flag)}[ \t]*[\\?\+\:\!]?=(?:.*\\\n)*.*$\n?/, "", false)
         errors << "expected to remove #{flag.inspect}"
       end
     end
@@ -58,6 +58,6 @@ module StringInreplaceExtension
 
   # Finds the specified variable
   def get_make_var(flag)
-    self[/^#{Regexp.escape(flag)}[ \t]*[\\?\+\:\!]?=[ \t]*(.*)$/, 1]
+    self[/^#{Regexp.escape(flag)}[ \t]*[\\?\+\:\!]?=[ \t]*((?:.*\\\n)*.*)$/, 1]
   end
 end
diff --git a/Library/Homebrew/test/inreplace_spec.rb b/Library/Homebrew/test/inreplace_spec.rb
index 7b5901b94a..965cd0035b 100644
--- a/Library/Homebrew/test/inreplace_spec.rb
+++ b/Library/Homebrew/test/inreplace_spec.rb
@@ -53,6 +53,24 @@ describe StringInreplaceExtension do
           EOS
         end
       end
+
+      context "with newlines" do
+        let(:string) do
+          <<~'EOS'
+            CFLAGS = -Wall -O2 \
+                     -DSOME_VAR=1
+            LDFLAGS = -lcrypto -lssl
+          EOS
+        end
+
+        it "is successfully replaced" do
+          subject.change_make_var! "CFLAGS", "-O3"
+          expect(subject).to eq <<~EOS
+            CFLAGS=-O3
+            LDFLAGS = -lcrypto -lssl
+          EOS
+        end
+      end
     end
 
     context "empty flag between other flags" do
@@ -146,6 +164,23 @@ describe StringInreplaceExtension do
           EOS
         end
       end
+
+      context "with newlines" do
+        let(:string) do
+          <<~'EOS'
+            CFLAGS = -Wall -O2 \
+                     -DSOME_VAR=1
+            LDFLAGS = -lcrypto -lssl
+          EOS
+        end
+
+        it "is successfully removed" do
+          subject.remove_make_var! "CFLAGS"
+          expect(subject).to eq <<~EOS
+            LDFLAGS = -lcrypto -lssl
+          EOS
+        end
+      end
     end
 
     context "multiple flags" do
@@ -194,6 +229,20 @@ describe StringInreplaceExtension do
         expect(subject.get_make_var("CFLAGS")).to eq("-Wall -O2")
       end
     end
+
+    context "with newlines" do
+      let(:string) do
+        <<~'EOS'
+          CFLAGS = -Wall -O2 \
+                   -DSOME_VAR=1
+          LDFLAGS = -lcrypto -lssl
+        EOS
+      end
+
+      it "extracts the value for a given variable" do
+        expect(subject.get_make_var("CFLAGS")).to match(/^-Wall -O2 \\\n +-DSOME_VAR=1$/)
+      end
+    end
   end
 
   describe "#sub!" do