[PATCH] completion: Add support for custom header prefixes

[Per Modin <per@modin.io>]

Append custom search query prefixes, if any, to the standard set of
terms used for searching. Applies to both bash and zsh, and is checked
with Awk and GNU Awk.
---
 completion/notmuch-completion.bash | 4 ++++
 completion/zsh/_notmuch            | 3 +++
 2 files changed, 7 insertions(+)

diff --git a/completion/notmuch-completion.bash b/completion/notmuch-completion.bash
index 3748846e..cb363719 100644
--- a/completion/notmuch-completion.bash
+++ b/completion/notmuch-completion.bash
@@ -123,6 +123,10 @@ _notmuch_search_terms()
 	    ;;
 	*)
 	    local search_terms="from: to: subject: attachment: mimetype: tag: id: thread: folder: path: date: lastmod: query: property:"
+
+	    # append custom search terms, if any
+	    search_terms="${search_terms}$(notmuch config list | awk -F'[.=]' '/index\.header\./ { printf " %s:", $3 }')"
+
 	    compopt -o nospace
 	    COMPREPLY=( $(compgen -W "${search_terms}" -- ${cur}) )
 	    ;;
diff --git a/completion/zsh/_notmuch b/completion/zsh/_notmuch
index 0bdd7f77..d779ceb5 100644
--- a/completion/zsh/_notmuch
+++ b/completion/zsh/_notmuch
@@ -112,6 +112,9 @@ _notmuch_search_term() {
     'from' 'to' 'subject' 'attachment' 'mimetype' 'tag' 'id' 'thread' 'path' 'folder' 'date' 'lastmod' 'query' 'property'
   )
 
+  # append custom search terms, if any
+  notmuch_search_terms+=("${(@f)$(notmuch config list | awk -F'[.=]' '/index\.header\./ { print $3 }')}")
+
   if compset -P '(#b)([^:]#):'; then
     if (( $+functions[_notmuch_term_$match[1]] )); then
       _notmuch_term_$match[1] && ret=0
-- 
2.43.0