styles/iceg: handle the case of an unset GST_ENV when testing for it

diff --git a/styles/iceg b/styles/iceg
index 2a8d17a..e72017b 100644 (file)
--- a/styles/iceg
+++ b/styles/iceg
@@ -18,7 +18,7 @@ PS1+="[${BOLD_RED}\${ERR}${BOLD_CYAN}]"
 # GST_ENV is set before the gst-build subshell starts and is valid until the
 # subshell exits, so it's OK to only check it once and for all when the prompt
 # is defined.
-if [[ -n "${GST_ENV}" ]];
+if [[ -n "${GST_ENV-}" ]];
 then
   PS1+="${MODE_GRAPHIC}${HORIZ_LINE}${MODE_DEFAULT}[ ${BOLD_MAGENTA}${GST_ENV}${BOLD_CYAN} ]"
 fi