ceph-backport.sh/PR quoting: eliminate unwanted newlines

Sometimes the PR body has multiple newlines which do not need
to be quoted. Also, the way we interact with the GitHub API, we
were getting some newline duplication.

This patch reduces all clumps of multiple blank lines down to a single
blank line.

Signed-off-by: Nathan Cutler <ncutler@suse.com>

diff --git a/src/script/ceph-backport.sh b/src/script/ceph-backport.sh
index 5a34b13b6b110cb644efcb576b37a7ac6a4e915e..fb8900fb0185178b36366c738a1527579a709946 100755 (executable)
--- a/src/script/ceph-backport.sh
+++ b/src/script/ceph-backport.sh
@@ -320,6 +320,29 @@ function clear_line {
     log overwrite "                                                                             \r"
 }
 
+function clip_pr_body {
+    local pr_body="$*"
+    local clipped=""
+    local last_line_was_blank=""
+    local line=""
+    local pr_json_tempfile=$(mktemp)
+    echo "$pr_body" | sed -n '/<!--.*/q;p' > "$pr_json_tempfile"
+    while IFS= read -r line; do
+        if [ "$(trim_whitespace "$line")" ] ; then
+            last_line_was_blank=""
+            clipped="${clipped}${line}\n"
+        else
+            if [ "$last_line_was_blank" ] ; then
+                true
+            else
+                clipped="${clipped}\n"
+            fi
+        fi
+    done < "$pr_json_tempfile"
+    rm "$pr_json_tempfile"
+    echo "$clipped"
+}
+
 function debug {
     log debug "$@"
 }
@@ -388,12 +411,8 @@ function existing_pr_routine {
         info "Cowardly refusing to work on a backport to $base_branch"
         false
     fi
-    pr_json_tempfile=$(mktemp)
-    echo "$pr_body" | sed -n '/<!--.*/q;p' > "$pr_json_tempfile"
-    # clipped_pr_body=$(cat "$pr_json_tempfile" | xargs)
-    clipped_pr_body="$(xargs < "$pr_json_tempfile")"
-    rm "$pr_json_tempfile"
-    verbose_en "Clipped body of existing PR ${backport_pr_number}:\n${clipped_pr_body}\n"
+    clipped_pr_body="$(clip_pr_body "$pr_body")"
+    verbose_en "Clipped body of existing PR ${backport_pr_number}:\n${clipped_pr_body}"
     if [[ "$backport_pr_title" =~ ^${milestone}: ]] ; then
         verbose "Existing backport PR ${backport_pr_number} title has ${milestone} prepended"
     else
@@ -1013,6 +1032,15 @@ function tracker_component_was_updated {
     echo "$was_updated"
 }
 
+function trim_whitespace {
+    local var="$*"
+    # remove leading whitespace characters
+    var="${var#"${var%%[![:space:]]*}"}"
+    # remove trailing whitespace characters
+    var="${var%"${var##*[![:space:]]}"}"
+    echo -n "$var"
+}
+
 function troubleshooting_advice {
     cat <<EOM
 Troubleshooting notes