Add fallback widget for bash < 4 (#375)

shell/navi.plugin.bash

@@ -16,4 +16,31 @@ _call_navi() {
     fi
 }
 
-bind -x '"\C-g": _call_navi'
+__call_navi_legacy_versions() {
+    local -r result="$(navi --print)"
+    local -r linecount="$(echo "$result" | wc -l)"
+
+    if [[ "$linecount" -lt 2 ]]; then
+        printf "%s" "$result"
+        return 0
+    fi
+
+    IFS=$'\n'
+    local i=1;
+    for line in $result; do
+        if echo "$line" | grep -q '\\$'; then
+            printf "${line::-1} "
+        elif [[ "$i" -eq "$linecount" ]]; then
+            printf "$line "
+        else 
+            printf "${line}; "
+        fi
+        i=$((i+1))
+    done
+}
+
+if [ ${BASH_VERSION:0:1} -lt 4 ]; then 
+    bind '"\C-g": " \C-b\C-k \C-u`__call_navi_legacy_versions`\e\C-e\C-a\C-y\C-h\C-e\e \C-y\ey\C-x\C-x\C-f"'
+else
+    bind -x '"\C-g": _call_navi'
+fi