Preserve previous Additional Boards Manager URLs value

Previously, install_package would overwrite the Additional Boards Manager URLs preference value. 3rd party hardware packages installed via Boards Manager are not correctly recognized by the Arduino IDE if their URL is not in the preferences so this was problematic when multiple 3rd party packages were installed via install_package.

Author: per1234

arduino-ci-script.sh

@@ -532,11 +532,28 @@ function install_package()
 
       # If defined add the boards manager URL to preferences
       if [[ "$packageURL" != "" ]]; then
+        # Get the current Additional Boards Manager URLs preference value so it won't be overwritten when the new URL is added
+        local priorBoardsmanagerAdditionalURLs
+        if [[ "$ARDUINO_CI_SCRIPT_VERBOSITY_LEVEL" -eq 0 ]]; then
+          priorBoardsmanagerAdditionalURLs=$("${ARDUINO_CI_SCRIPT_APPLICATION_FOLDER}/${ARDUINO_CI_SCRIPT_IDE_INSTALLATION_FOLDER}/${ARDUINO_CI_SCRIPT_ARDUINO_COMMAND}" --get-pref boardsmanager.additional.urls 2>/dev/null | tail --lines=1)
+        elif [[ "$ARDUINO_CI_SCRIPT_VERBOSITY_LEVEL" -eq 1 ]]; then
+          priorBoardsmanagerAdditionalURLs=$("${ARDUINO_CI_SCRIPT_APPLICATION_FOLDER}/${ARDUINO_CI_SCRIPT_IDE_INSTALLATION_FOLDER}/${ARDUINO_CI_SCRIPT_ARDUINO_COMMAND}" --get-pref boardsmanager.additional.urls | tail --lines=1)
+        else
+          priorBoardsmanagerAdditionalURLs=$("${ARDUINO_CI_SCRIPT_APPLICATION_FOLDER}/${ARDUINO_CI_SCRIPT_IDE_INSTALLATION_FOLDER}/${ARDUINO_CI_SCRIPT_ARDUINO_COMMAND}" --get-pref boardsmanager.additional.urls | tee /dev/tty | tail --lines=1)
+        fi
+        local -r blankregex="^[ ]*$"
+        if [[ "$priorBoardsmanagerAdditionalURLs" =~ $blankregex ]]; then
+          # There is no previous Additional Boards Manager URLs preference value
+          local boardsmanagerAdditionalURLs="$packageURL"
+        else
+          # There is a previous Additional Boards Manager URLs preference value so append the new one to the end of it
+          local boardsmanagerAdditionalURLs="${priorBoardsmanagerAdditionalURLs},${packageURL}"
+        fi
 
         # grep returns 1 when a line matches the regular expression so it's necessary to unset errexit
         set +o errexit
         # shellcheck disable=SC2086
-        eval \"${ARDUINO_CI_SCRIPT_APPLICATION_FOLDER}/${ARDUINO_CI_SCRIPT_IDE_INSTALLATION_FOLDER}/${ARDUINO_CI_SCRIPT_ARDUINO_COMMAND}\" --pref boardsmanager.additional.urls="$packageURL" --save-prefs "$ARDUINO_CI_SCRIPT_VERBOSITY_REDIRECT" | tr -Cd '[:print:]\n\t' | grep --extended-regexp --invert-match "$ARDUINO_CI_SCRIPT_ARDUINO_OUTPUT_FILTER_REGEX"; local -r arduinoPreferenceSettingExitStatus="${PIPESTATUS[0]}"
+        eval \"${ARDUINO_CI_SCRIPT_APPLICATION_FOLDER}/${ARDUINO_CI_SCRIPT_IDE_INSTALLATION_FOLDER}/${ARDUINO_CI_SCRIPT_ARDUINO_COMMAND}\" --pref boardsmanager.additional.urls="$boardsmanagerAdditionalURLs" --save-prefs "$ARDUINO_CI_SCRIPT_VERBOSITY_REDIRECT" | tr -Cd '[:print:]\n\t' | grep --extended-regexp --invert-match "$ARDUINO_CI_SCRIPT_ARDUINO_OUTPUT_FILTER_REGEX"; local -r arduinoPreferenceSettingExitStatus="${PIPESTATUS[0]}"
         set -o errexit
         # this is required because otherwise the exit status of arduino is ignored
         if [[ "$arduinoPreferenceSettingExitStatus" != "$ARDUINO_CI_SCRIPT_SUCCESS_EXIT_STATUS" ]]; then