release-notes.pl: ignore dupes on input and output

Re-running this script now makes it track the already mentioned
changelog entries and not add them again even if the git log contains
them.

This makes the script better handle reruns in a release branch after
rebasing on a later version of master.

Closes #17937

scripts/release-notes.pl

@@ -61,16 +61,29 @@ my @releasenotes=`cat RELEASE-NOTES`;
 my @o; # the entire new RELEASE-NOTES
 my @refused; # [num] = [2 bits of use info]
 my @refs; # [number] = [URL]
+my %dupe;
 for my $l (@releasenotes) {
     if($l =~ /^ o .*\[(\d+)\]/) {
         # referenced, set bit 0
         $refused[$1]=1;
+        my $m = $l;
+        chomp $m;
+        $m =~ s/^ o //;
+        $m =~ s/ \[\d+\]$//;
+        $dupe{$m} = 1; # mark this as present
     }
     elsif($l =~ /^ \[(\d+)\] = (.*)/) {
         # listed in a reference, set bit 1
         $refused[$1] |= 2;
         $refs[$1] = $2;
     }
+    # mention without reference
+    elsif($l =~ /^ o (.*)/) {
+        my $m = $l;
+        chomp $m;
+        $m =~ s/^ o //;
+        $dupe{$m} = 1; # mark this as present
+    }
 }
 
 # Return a new fresh reference number
@@ -156,6 +169,11 @@ sub onecommit {
     my ($short)=@_;
     my $ref;
 
+    if($dupe{$short}) {
+        # this git commit message was found in the file
+        return;
+    }
+
     if($bug[0]) {
         $ref = $bug[0];
     }
@@ -185,6 +203,11 @@ for my $l (@releasenotes) {
         push @o, $l;
         push @o, "\n";
         for my $f (@line) {
+            if($dupe{$f}) {
+                # this item is already listed
+                next;
+            }
+
             push @o, sprintf " o %s%s\n", $f,
                 $moreinfo{$f}? sprintf(" [%d]", $moreinfo{$f}): "";
             $refused[$moreinfo{$f}]=3;