parsing - 如何在 Web 服务器上的请求 URI 中解码保留的转义字符？

Question

很明显，Web 服务器必须解码任何转义的非保留字符(例如字母数字等)才能进行 URI 比较。例如，http://www.example.com/~user/index.htm应与 http://www.example.com/%7Euser/index.htm 相同.
我的问题是，我们将如何处理转义的保留字符？
一个例子是 %2F , 或 / .如果有 %2F在请求 URI 中，Web 服务器的解析器是否应该将其替换为 / ?在上面的例子中，这意味着 http://www.example.com/~user%2Findex.htm将与 http://www.example.com/~user/index.htm 相同?尽管我在 Apache 服务器(2.2.17 Unix)上尝试过它，但它似乎给出了“404 Not Found”错误。
那么这是否意味着 %2F和其他转义保留字符应单独保留(至少在 URI 比较之前)？
背景资料:
RFC 2616 (HTTP 1.1) 中有两个地方提到了转义解码问题:

The Request-URI is transmitted in the format specified in section 3.2.1. If the Request-URI is encoded using the “% HEX HEX” encoding [42], the origin server MUST decode the Request-URI in order to properly interpret the request. Servers SHOULD respond to invalid Request-URIs with an appropriate status code.

和

Characters other than those in the “reserved” and “unsafe” sets (see RFC 2396 [42]) are equivalent to their “"%" HEX HEX” encoding.

(根据 http://trac.tools.ietf.org/wg/httpbis/trac/ticket/2“不安全”是一个错误，应该从规范中删除。所以我们在这里只看“保留”。)
仅供引用，RFC 2396 中此类字符的定义:

reserved = ";" | "/" | "?" | ":" | "@" | "&" | "=" | "+" | "$" | ","

unreserved = alphanum | mark

mark = "-" | "_" | "." | "!" | "˜" | "*" | "’" | "(" | ")"

Answer 1

tl;博士:
解码百分比编码的非保留字符，
保留百分比编码的保留字符。

URI 标准是 STD 66 ，目前是 RFC 3986 .
Section 6是关于归一化和比较，其中 section 6.2.2.2解释了如何处理百分比编码的八位字节:

These URIs should be normalized by decoding any percent-encoded octet that corresponds to an unreserved character […]

正如 section 2 中明确所述(粗体强调我的):

Unreserved characters :

URIs that differ in the replacement of an unreserved character with its corresponding percent-encoded US-ASCII octet are equivalent

Reserved characters :

URIs that differ in the replacement of a reserved character with its corresponding percent-encoded octet are not equivalent.