1 files changed, 30 insertions, 30 deletions
diff --git a/pkgs/development/interpreters/lua-5/setup-hook.sh b/pkgs/development/interpreters/lua-5/setup-hook.sh
index 3989bedffdb..f7e56b62ac9 100644
--- a/pkgs/development/interpreters/lua-5/setup-hook.sh
+++ b/pkgs/development/interpreters/lua-5/setup-hook.sh
@@ -1,47 +1,47 @@
 # set -e
 
 nix_print() {
-    if [ ${NIX_DEBUG:-0} -ge $1 ]; then
-        echo "$2"
-    fi
+  if [ ${NIX_DEBUG:-0} -ge $1 ]; then
+    echo "$2"
+  fi
 }
 
 nix_debug() {
-    nix_print 3 "$1"
+  nix_print 3 "$1"
 }
 
 addToLuaSearchPathWithCustomDelimiter() {
-    local varName="$1"
-    local absPattern="$2"
-    # delete longest match starting from the lua placeholder '?'
-    local topDir="${absPattern%%\?*}"
+  local varName="$1"
+  local absPattern="$2"
+  # delete longest match starting from the lua placeholder '?'
+  local topDir="${absPattern%%\?*}"
 
-    # export only if the folder exists else LUA_PATH grows too big
-    if  [ ! -d "$topDir" ]; then return; fi
+  # export only if the folder exists else LUA_PATH/LUA_CPATH grow too large
+  if [[ ! -d "$topDir" ]]; then return; fi
 
-    export "${varName}=${!varName:+${!varName};}${absPattern}"
+  # export only if we haven't already got this dir in the search path
+  if [[ ${!varName} == *"$absPattern"* ]]; then return; fi
+
+  export "${varName}=${!varName:+${!varName};}${absPattern}"
 }
 
 addToLuaPath() {
-    local dir="$1"
-
-    if [[ ! -d "$dir" ]]; then
-        nix_debug "$dir not a directory abort"
-        return 0
-    fi
-    cd "$dir"
-    for pattern in @luapathsearchpaths@;
-    do
-        addToLuaSearchPathWithCustomDelimiter NIX_LUA_PATH "$PWD/$pattern"
-    done
-
-    # LUA_CPATH
-    for pattern in @luacpathsearchpaths@;
-    do
-        addToLuaSearchPathWithCustomDelimiter NIX_LUA_CPATH "$PWD/$pattern"
-    done
-    cd - >/dev/null
+  local dir="$1"
+
+  if [[ ! -d "$dir" ]]; then
+    nix_debug "$dir not a directory abort"
+    return 0
+  fi
+  cd "$dir"
+  for pattern in @luapathsearchpaths@; do
+    addToLuaSearchPathWithCustomDelimiter LUA_PATH "$PWD/$pattern"
+  done
+
+  # LUA_CPATH
+  for pattern in @luacpathsearchpaths@; do
+    addToLuaSearchPathWithCustomDelimiter LUA_CPATH "$PWD/$pattern"
+  done
+  cd - >/dev/null
 }
 
 addEnvHooks "$hostOffset" addToLuaPath
-