fix: Update update_changes.sh

Author: effigies

.maint/update_changes.sh

@@ -1,7 +1,7 @@
 #!/bin/bash
 #
 # Collects the pull-requests since the latest release and
-# aranges them in the CHANGES.rst file.
+# aranges them in the CHANGES.rst.txt file.
 #
 # This is a script to be run before releasing a new version.
 #
@@ -19,8 +19,29 @@ if [[ "$UPCOMING" == "0" ]]; then
     head -n3  CHANGES.rst >> newchanges
 fi
 
+# Elaborate today's release header
+HEADER="$1 ($(date '+%B %d, %Y'))"
+echo $HEADER >> newchanges
+echo $( printf "%${#HEADER}s" | tr " " "=" ) >> newchanges
+echo "" >> newchanges
+
 # Search for PRs since previous release
-git show --pretty='format:  * %b %s'  HEAD | sed 's/Merge pull request \#\([^\d]*\)\ from\ .*/(\#\1)/' >> newchanges
+MERGE_COMMITS=$( git log --grep="Merge pull request\|(#.*)$" `git describe --tags --abbrev=0`..HEAD --pretty='format:%h' )
+for COMMIT in ${MERGE_COMMITS//\n}; do
+    SUB=$( git log -n 1 --pretty="format:%s" $COMMIT )
+    if ( echo $SUB | grep "^Merge pull request" ); then
+        # Merge commit
+        PR=$( echo $SUB | sed -e "s/Merge pull request \#\([0-9]*\).*/\1/" )
+        TITLE=$( git log -n 1 --pretty="format:%b" $COMMIT )
+    else
+        # Squashed merge
+        PR=$( echo $SUB | sed -e "s/.*(\#\([0-9]*\))$/\1/" )
+        TITLE=$( echo $SUB | sed -e "s/\(.*\) (\#[0-9]*)$/\1/" )
+    fi
+    echo "  * $TITLE (#$PR)" >> newchanges
+done
+echo >> newchanges
+echo >> newchanges
 
 # Add back the Upcoming header if it was present
 if [[ "$UPCOMING" == "0" ]]; then
@@ -31,4 +52,3 @@ fi
 
 # Replace old CHANGES.rst with new file
 mv newchanges CHANGES.rst
-