Refactor percent_decode as inverse of percent_encode

lib/http_tools.sh

@@ -491,8 +491,8 @@ get_header_value () {
 }
 
 #######################################################################
-# This function percent-encodes all characters except the "Unreserved 
-# Characters" defined in section 2.3 of RFC 3986.
+# This function percent-encodes all characters in its string argument
+# except the "Unreserved Characters" defined in section 2.3 of RFC 3986.
 #
 # See: https://gist.github.com/cdown/1163649
 #      https://en.wikipedia.org/wiki/Percent-encoding
@@ -523,7 +523,9 @@ percent_encode () {
 }
 
 #######################################################################
-# This function percent-decodes all percent-encoded characters.
+# This function is the inverse of the percent_encode function, that 
+# is, it percent-decodes all percent-encoded characters in its string 
+# argument.
 #######################################################################
 percent_decode () {
     # percent_decode <string>
@@ -534,15 +536,7 @@ percent_decode () {
 		return 2
 	fi
 
-	local encoded_string
-
-	# the percent_encode function doesn't convert spaces to
-	# plus signs (+) but the input string to the percent_decode 
-	# function may have been encoded in some other manner so we
-	# first decode plus signs (+) into spaces
-    encoded_string="${1//+/ }"
-
-    printf '%b' "${encoded_string//%/\\x}"
+    printf '%b' "${1//%/\\x}"
 }
 
 # DEPRECATED: Use percent_encode and percent_decode instead.