Fix word wrapping determinism on BSD / Linux

fmt behaves totally differently depending on the version and on the
OS, use fold instead that has a consistent behaviour accross platform.

Tested with bazel test //scripts/release/... on OSX and Linux.

--
MOS_MIGRATED_REVID=101567574

1 files changed, 4 insertions, 10 deletions

diff --git a/scripts/release/relnotes.sh b/scripts/release/relnotes.sh
index 15abbd1cb7..7071f7186a 100755
--- a/scripts/release/relnotes.sh
+++ b/scripts/release/relnotes.sh
@@ -97,16 +97,10 @@ function get_release_notes() {
   done
 }
 
-# fmt behaves a bit different on GNU/Linux than on BSDs.
-if [ "$(uname -s | tr 'A-Z' 'a-z')" = "linux" ]; then
-  function wrap_text() {
-    fmt -w $1 -g $1
-  }
-else
-  function wrap_text() {
-    fmt -w $1
-  }
-fi
+# fmt behaves differently on *BSD and on GNU/Linux, use fold.
+function wrap_text() {
+  fold -s -w $1 | sed 's/ *$//'
+}
 
 # Returns the list of release notes in arguments into a list of points in
 # a markdown list. The release notes are wrapped to 70 characters so it