Fix aliases with whitespace

And document how that stuff works.

Fixes #2220

Also, the string stuff is cool.

2 files changed, 61 insertions, 60 deletions

diff --git a/doc_src/alias.txt b/doc_src/alias.txt
index 028277a3..cbb9508e 100644
--- a/doc_src/alias.txt
+++ b/doc_src/alias.txt
@@ -18,6 +18,8 @@ alias NAME=DEFINITION
 
 You cannot create an alias to a function with the same name.
 
+Note that spaces need to be escaped in the call to alias just like in the commandline _even inside the quotes_.
+
 
 \subsection alias-example Example
 
@@ -31,4 +33,8 @@ alias rmi "rm -i"
 function rmi
     rm -i $argv
 end
+
+# This needs to have the spaces escaped or "Chrome.app..." will be seen as an argument to "/Applications/Google":
+
+alias chrome='/Applications/Google\ Chrome.app/Contents/MacOS/Google\ Chrome banana'
 \endfish
diff --git a/share/functions/alias.fish b/share/functions/alias.fish
index 2dc86b1b..11fdd164 100644
--- a/share/functions/alias.fish
+++ b/share/functions/alias.fish
@@ -1,70 +1,65 @@
+function alias --description 'Legacy function for creating shellscript functions using an alias-like syntax'
+    if count $argv > /dev/null
+        switch $argv[1]
+            case -h --h --he --hel --help
+                __fish_print_help alias
+                return 0
+        end
+    end
 
-function alias --description "Legacy function for creating shellscript functions using an alias-like syntax"
+    set -l name
+    set -l body
+    set -l prefix
+    set -l first_word
+    switch (count $argv)
 
-	if count $argv >/dev/null
-		switch $argv[1]
-			case -h --h --he --hel --help
-				__fish_print_help alias
-				return 0
-		end
-	end
+        case 0
+            echo "Fish implements aliases using functions. Use 'functions' builtin to see list of functions and 'functions function_name' to see function definition, type 'help alias' for more information."
+            return 1
+        case 1
+            set -l tmp (string replace -r "=" '\n' -- $argv) ""
+            set name $tmp[1]
+            set body $tmp[2]
 
-	set -l name
-	set -l body
-	set -l prefix
-        set -l first_word
-	switch (count $argv)
+        case 2
+            set name $argv[1]
+            set body $argv[2]
 
-		case 0
- 			echo "Fish implements aliases using functions. Use 'functions' builtin to see list of functions and 'functions function_name' to see function definition, type 'help alias' for more information."
-			return 1
-		case 1
-			# Some seds (e.g. on Mac OS X), don't support \n in the RHS
-			# Use a literal newline instead
-			# http://sed.sourceforge.net/sedfaq4.html#s4.1
-                        # The extra '' at the end is so $tmp[2] is guaranteed to work
-                        set -l tmp (echo $argv|sed -e 's/\([^=]\{0,1\}\)=/\1\
-/') ''
-			set name $tmp[1]
-			set body $tmp[2]
+        case \*
+            printf ( _ "%s: Expected one or two arguments, got %d\n") alias (count $argv)
+            return 1
+    end
 
-		case 2
-			set name $argv[1]
-			set body $argv[2]
+    # sanity check
+    if test -z "$name"
+        printf ( _ "%s: Name cannot be empty\n") alias
+        return 1
+    else if test -z "$body"
+        printf ( _ "%s: Body cannot be empty\n") alias
+        return 1
+    end
 
-		case \*
-			printf ( _ "%s: Expected one or two arguments, got %d\n") alias (count $argv)
-			return 1
-	end
+    # Extract the first command from the body
+	# This is supposed to replace all non-escaped (i.e. preceded by an odd number of `\`) spaces with a newline
+	# so it splits on them
+	set -l tmp (string replace -ra "([^\\\ ])((\\\\\\\)*) " '$1\n' $body)
+    set first_word (string trim $tmp[1])
+    if set -q tmp[2]
+        set body $tmp[2..-1]
+    else
+        set body
+    end
 
-        # sanity check
-        if test -z "$name"
-                printf ( _ "%s: Name cannot be empty\n") alias
-                return 1
-        else if test -z "$body"
-                printf ( _ "%s: Body cannot be empty\n") alias
-                return 1
-        end
+    # Prevent the alias from immediately running into an infinite recursion if
+    # $body starts with the same command as $name.
 
-        # Extract the first command from the body
-        switch $body
-                case \*\ \* \*\t\*
-                        # note: strip leading spaces if present
-                        set first_word (echo $body|sed -e 's/^[[:space:]]\{1,\}//;s/[[:space:]].*//;q')
-                case '*'
-                        set first_word $body
+    if test $first_word = $name
+        if contains $name (builtin --names)
+            set prefix builtin
+        else
+            set prefix command
         end
-
-	# Prevent the alias from immediately running into an infinite recursion if
-	# $body starts with the same command as $name.
-
-        if test $first_word = $name
-                if contains $name (builtin --names)
-                        set prefix builtin
-                else
-                        set prefix command
-                end
-	end
-
-        eval "function $name --wraps $first_word; $prefix $body \$argv; end"
+    end
+    eval "function $name --wraps $first_word; $prefix $first_word $body \$argv; end"
 end
+