Bash script says version is not supported, even though it is

Created by: ggerganov

I observe the following issue:

$ ./patch.sh
Detected nvidia driver version: 396.54
Patch for this (396.54) nvidia driver not found.
Available patches for:
390.87
396.26
396.24
410.48
415.25
415.18
375.39
410.57
410.73
396.54
410.78
410.79
396.37

Notice that the 396.54 is supported. However the script aborts with error.

$ lsb_release --all
No LSB modules are available.
Distributor ID:	Ubuntu
Description:	Ubuntu 12.04.3 LTS
Release:	12.04
Codename:	precise

$ bash --version
GNU bash, version 4.2.25(1)-release (x86_64-pc-linux-gnu)

I'm not a bash expert, but I was able to fix this with the following patch:

$ git diff
diff --git a/patch.sh b/patch.sh
index 907225b..2a7550a 100755
--- a/patch.sh
+++ b/patch.sh
@@ -79,7 +79,7 @@ fi

 echo "Detected nvidia driver version: $driver_version"

-if [[ ! -v "patch_list[$driver_version]" || ! -v "object_list[$driver_version]" ]]; then
+if [[ ! "${patch_list[$driver_version]+isset}" || ! "${object_list[$driver_version]+isset}" ]]; then
     echo "Patch for this ($driver_version) nvidia driver not found." 1>&2
     echo "Available patches for: " 1>&2
     for drv in "${!patch_list[@]}"; do

Now it works flawlessly.