Merge branch '5.4' into 6.0

* 5.4:
  Support completion for bash functions

Author: derrabus

src/Symfony/Component/Console/Resources/completion.bash

@@ -11,13 +11,14 @@ _sf_{{ COMMAND_NAME }}() {
     local sf_cmd="${COMP_WORDS[0]}"
 
     # for an alias, get the real script behind it
-    if [[ $(type -t $sf_cmd) == "alias" ]]; then
+    sf_cmd_type=$(type -t $sf_cmd)
+    if [[ $sf_cmd_type == "alias" ]]; then
         sf_cmd=$(alias $sf_cmd | sed -E "s/alias $sf_cmd='(.*)'/\1/")
-    else
+    elif [[ $sf_cmd_type == "file" ]]; then
         sf_cmd=$(type -p $sf_cmd)
     fi
 
-    if [ ! -x "$sf_cmd" ]; then
+    if [[ $sf_cmd_type != "function" && ! -x $sf_cmd ]]; then
         return 1
     fi