Fix stashing aliases with a space in double quotes

lib/varstash

@@ -108,6 +108,7 @@ function stash() {
             local alias_def="$(eval alias $stash_which 2>/dev/null)"
             if [[ -n $alias_def ]]; then
                 alias_def=${alias_def#alias }
+                alias_def=$(echo "$alias_def" | sed 's/"/\\&/g') # Escape double quotes
                 eval "__varstash_alias__$stash_name=\"$alias_def\""
                 local stashed=1
             fi

tests/varstash-alias.t

@@ -13,9 +13,9 @@ Setup test environment.
 
 Aliases should be stashed.
 
-  $ alias some_alias="echo ORIG_ALIAS"
+  $ alias some_alias='echo "ORIG ALIAS"'
   $ some_alias
-  ORIG_ALIAS
+  ORIG ALIAS
   $ cd .
   ENTER
   $ some_alias
@@ -23,13 +23,13 @@ Aliases should be stashed.
   $ cd ..
   LEAVE
   $ some_alias
-  ORIG_ALIAS
+  ORIG ALIAS
 
 Aliases should be stashed, if there are also environment variables.
 
   $ some_alias=ENV_VAR
   $ some_alias
-  ORIG_ALIAS
+  ORIG ALIAS
   $ cd sub
   ENTER
   $ type -w some_alias