make: different treatment for escaped NL in macro in command

Austin Group defect report 1549 has been accepted.  It requires
that an escaped newline inside a macro expansion in a command is
replaced by a space.  Other escaped newlines in commands are
left in place, as before.

1 files changed, 13 insertions, 0 deletions

diff --git a/testsuite/make.tests b/testsuite/make.tests
index 35d3b7149..8b46faf3c 100755
--- a/testsuite/make.tests
+++ b/testsuite/make.tests
@@ -307,6 +307,19 @@ target: file1 .WAIT file2
 '
 cd .. || exit 1; rm -rf make.tempdir 2>/dev/null
 
+# Escaped newlines inside macro expansions in commands get different
+# treatment than those outside.  In POSIX 2017 the output is 'a b ab'.
+testing "make replace escaped NL in macro in command with space" \
+        "make -f -" \
+        "a b a b\n" "" '
+M=word
+N=${M:word=a\
+b}
+target:
+        @echo ${N} ${M:word=a\
+b}
+'
+
 testing "make double-colon rule" \
         "make -f -" "target1\ntarget2\n" "" '
 target::