pw-apply: Use awk for multi-line subject line extraction

Instead of using experimental `grep -P` which doesn't work in some
distros, do it with line-by-line AWK script which collects all line
beginning with the line that starts with "Subject: " and ending before
hitting the line starting with another "<keyword>: ". This works for
single-line and multi-line subjects.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

1 files changed, 1 insertions, 1 deletions

diff --git a/pw-apply b/pw-apply
index f174a96..27fe528 100755
--- a/pw-apply
+++ b/pw-apply
@@ -183,7 +183,7 @@ if [ ! -z "$merge" ]; then
 	    author=$(echo "${BASH_REMATCH[1]}" | base64 -d)
     fi
     # Extract cover letter subject, potentially split into two lines
-    branch_name=$(grep -Pzo '(?<=^Subject: ).*?\n?.*?(?=\n\w+: )' cover.i | tr -d '\n' | cut -d']' -f2 | cut -c 2-)
+    branch_name=$(awk '/^\w+: / { subj=0 } /^Subject: / { subj = 1 } subj { print $0 }' cover.i | tr -d '\n' | cut -d']' -f2 | cut -c 2-)
     text=`grep -A300 'X-Mailing-List:' cover.i |tail --lines=+3|grep -B300 -E "^.*\([0-9]+\):$"|head --lines=-2`
     git commit --amend --signoff -F- <<EOF
 Merge branch '$branch_name'