ash: expand: Fix trailing newlines processing in backquote expanding
Upstream commit:
Date: Mon, 29 Apr 2019 19:13:37 +0500
expand: Fix trailing newlines processing in backquote expanding
According to POSIX.1-2008 we should remove newlines only at the end of
the substitution. Newlines-only substitions causes dash to remove
newlines before beggining of the substitution. The following code:
cat <<END
1
$(echo "")
2
END
prints "1<newline>2" instead of expected "1<newline><newline>2".
This patch fixes trailing newlines processing in backquote expanding.
Signed-off-by: Nikolai Merinov <n.merinov@inango-systems.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
diff --git a/shell/ash.c b/shell/ash.c
index 90496ba..dfe6d1c 100644
--- a/shell/ash.c
+++ b/shell/ash.c
@@ -6578,7 +6578,7 @@
/* Eat all trailing newlines */
dest = expdest;
- for (; dest > (char *)stackblock() && dest[-1] == '\n';)
+ for (; dest > ((char *)stackblock() + startloc) && dest[-1] == '\n';)
STUNPUTC(dest);
expdest = dest;
diff --git a/shell/ash_test/ash-psubst/tick_in_heredoc.right b/shell/ash_test/ash-psubst/tick_in_heredoc.right
new file mode 100644
index 0000000..7e7bac6
--- /dev/null
+++ b/shell/ash_test/ash-psubst/tick_in_heredoc.right
@@ -0,0 +1,5 @@
+1
+
+2
+
+3
diff --git a/shell/ash_test/ash-psubst/tick_in_heredoc.tests b/shell/ash_test/ash-psubst/tick_in_heredoc.tests
new file mode 100755
index 0000000..c8eb8f4
--- /dev/null
+++ b/shell/ash_test/ash-psubst/tick_in_heredoc.tests
@@ -0,0 +1,7 @@
+cat <<END
+1
+$(echo "")
+2
+`echo ""`
+3
+END
diff --git a/shell/hush_test/hush-psubst/tick_in_heredoc.right b/shell/hush_test/hush-psubst/tick_in_heredoc.right
new file mode 100644
index 0000000..7e7bac6
--- /dev/null
+++ b/shell/hush_test/hush-psubst/tick_in_heredoc.right
@@ -0,0 +1,5 @@
+1
+
+2
+
+3
diff --git a/shell/hush_test/hush-psubst/tick_in_heredoc.tests b/shell/hush_test/hush-psubst/tick_in_heredoc.tests
new file mode 100755
index 0000000..c8eb8f4
--- /dev/null
+++ b/shell/hush_test/hush-psubst/tick_in_heredoc.tests
@@ -0,0 +1,7 @@
+cat <<END
+1
+$(echo "")
+2
+`echo ""`
+3
+END
