chore(release.sh): Remove empty headings from NEWS.md

NEWS.md

@@ -14,6 +14,8 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/).
 
 ### Changed
 
+- **release.sh**: Remove noise (empty headings) in **NEWS.md** at release time
+
 ### Removed
 
 ## [1.6] - 2023-07-14
@@ -22,53 +24,31 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/).
 
 - Use command `opam env --switch=$it --set-switch`, so the env var `$OPAMSWITCH` is also set
 
-### Fixed
-
-### Changed
-
-### Removed
-
 ## [1.5] - 2023-07-12
 
-### Added
-
-### Fixed
-
 ### Changed
 
 - **README.md**: Use vanilla (not GitHub-flavored) Markdown syntax for snippets
 - Replace (redraw-display) with (force-mode-line-update t)
 - Memoize (opam-switch-mode-lighter) to speed-up mode-line updates
 
-### Removed
-
 ## [1.4] - 2023-07-11
 
 ### Added
 
 - (opam-switch-mode-lighter): Indicate the switch name in the minibuffer, closes [#11](https://github.com/ProofGeneral/opam-switch-mode/issues/11)
 
-### Fixed
-
 ### Changed
 
 - **README.md**: Document the feature from [1.3]
 
-### Removed
-
 ## [1.3] - 2023-07-11
 
 ### Added
 
 - New hook: opam-switch-before-change-opam-switch-hook
 - (opam-switch-set-switch): Call (run-hooks 'opam-switch-before-change-opam-switch-hook) before changing the env
 
-### Fixed
-
-### Changed
-
-### Removed
-
 ## [1.2] - 2023-07-11
 
 ### Added
@@ -88,8 +68,6 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/).
 - Change mode-bar's first element, so it expands to "OPSW - Opam Switch Mode"
 - **release.sh**: auto-update **NEWS.md**
 
-### Removed
-
 ## [1.1] - 2023-06-20
 
 ### Added
@@ -100,10 +78,6 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/).
 
 - tweaks and cleanups by [**@monnier**](https://github.com/monnier)
 
-### Changed
-
-### Removed
-
 ## [1.0] - 2022-11-15
 
 - Initial release, distributed on MELPA.

release.sh

@@ -7,7 +7,8 @@ set -eu
 perl_replace() {
     local str1="$1"
     local str2="$2"
-    perl -wpe 'BEGIN{$str1=shift @ARGV; $str2=shift @ARGV; $s1=quotemeta($str1); }; s/$s1/$str2/g;' "$str1" "$str2"
+    local slurp="${3:+0777}"
+    perl -wp"$slurp"e 'BEGIN{$str1=shift @ARGV; $str2=shift @ARGV; $s1=quotemeta($str1); }; s/$s1/$str2/g;' "$str1" "$str2"
 }
 
 tweak_changelog() {
@@ -18,6 +19,24 @@ tweak_changelog() {
     next_full="## [$next] - $(date -I)"
 
     if [ "$step" = '1' ]; then
+        local replace=(
+'### Added
+
+#'
+'### Fixed
+
+#'
+'### Changed
+
+#'
+'### Removed
+
+#')
+        local r
+        for r in "${replace[@]}"; do
+            cp -f "$file" "$file~"
+            perl_replace "$r" "#" "slurp" <"$file~" > "$file"
+        done
         local line_unreleased
         line_unreleased=$(grep "$file" -e 'Unreleased.*\.\.\.HEAD')
         local released_tmp
@@ -30,7 +49,7 @@ tweak_changelog() {
         perl_replace "$line_unreleased" "$released" <"$file~" > "$file"
 
     elif [ "$step" = '2' ]; then
-        local section="## [Unreleased]
+        local section='## [Unreleased]
 
 ### Added
 
@@ -40,12 +59,12 @@ tweak_changelog() {
 
 ### Removed
 
-"
+'
         local unreleased="[Unreleased]: https://github.com/ProofGeneral/opam-switch-mode/compare/$next...HEAD"
         cp -fv "$file" "$file~"
         perl_replace "$next_full" "$section$next_full" <"$file~" > "$file"
         cp -fv "$file" "$file~"
-        perl_replace "<!-- bottom -->" "<!-- bottom -->
+        perl_replace '<!-- bottom -->' "<!-- bottom -->
 $unreleased" <"$file~" > "$file"
 
     else