From fd3107447031049e44fa7a060f3990d16d69fc3d Mon Sep 17 00:00:00 2001
From: Parker Coates <coates@qps.nl>
Date: Mon, 16 Mar 2015 08:30:05 -0300
Subject: [PATCH 1/2] Use array reversal instead of array sorting.

There's no need to do a full numerical sort here, since we know the
keys will be in reverse numerical order, because (R) searches in last-
to-first order. Not a big deal, but this is just simpler and
presumably more efficient.

Also cleaned up a rather confusing comment about (on) being used to
remove duplicates, which it definitely doesn't.
---
 zsh-history-substring-search.zsh | 8 +++-----
 1 file changed, 3 insertions(+), 5 deletions(-)

diff --git a/zsh-history-substring-search.zsh b/zsh-history-substring-search.zsh
index fb381ad..4291614 100644
--- a/zsh-history-substring-search.zsh
+++ b/zsh-history-substring-search.zsh
@@ -200,12 +200,10 @@ function _history-substring-search-begin() {
     #
     # Find all occurrences of the search query in the history file.
     #
-    # (k) turns it an array of line numbers.
+    # (k) returns the "keys" (history index numbers) instead of the values
+    # (Oa) reverses the order, because (R) returns results reversed.
     #
-    # (on) seems to remove duplicates, which are default
-    #      options. They can be turned off by (ON).
-    #
-    _history_substring_search_matches=(${(kon)history[(R)(#$HISTORY_SUBSTRING_SEARCH_GLOBBING_FLAGS)*${_history_substring_search_query_escaped}*]})
+    _history_substring_search_matches=(${(kOa)history[(R)(#$HISTORY_SUBSTRING_SEARCH_GLOBBING_FLAGS)*${_history_substring_search_query_escaped}*]})
 
     #
     # Define the range of values that $_history_substring_search_match_index

From 13033d87a1f9773c55dfa3d71ed661a8a9b3d1f5 Mon Sep 17 00:00:00 2001
From: Parker Coates <coates@qps.nl>
Date: Mon, 16 Mar 2015 08:35:28 -0300
Subject: [PATCH 2/2] GH-19: Respect the HIST_FIND_NO_DUPS option.

This is the best way I've found to remove duplicate entries while
keeping the most recent occurence, but I'm not a ZSH expert. There may
be a more efficient way.
---
 zsh-history-substring-search.zsh | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/zsh-history-substring-search.zsh b/zsh-history-substring-search.zsh
index 4291614..57cc3a4 100644
--- a/zsh-history-substring-search.zsh
+++ b/zsh-history-substring-search.zsh
@@ -205,6 +205,15 @@ function _history-substring-search-begin() {
     #
     _history_substring_search_matches=(${(kOa)history[(R)(#$HISTORY_SUBSTRING_SEARCH_GLOBBING_FLAGS)*${_history_substring_search_query_escaped}*]})
 
+    # Remove duplicate entries (keeping on the most recent) if HIST_FIND_NO_DUPS is set.
+    if [[ -o HIST_FIND_NO_DUPS ]]; then
+        local -A unique_matches
+        for n in $_history_substring_search_matches; do
+            unique_matches[${history[$n]}]="$n"
+        done
+        _history_substring_search_matches=(${(@n)unique_matches})
+    fi
+
     #
     # Define the range of values that $_history_substring_search_match_index
     # can take: [0, $_history_substring_search_matches_count_plus].