Fixed incorrect handling of reserved chars.

* src/iri.c (do_conversion): Call url_unescape_except_reserved,
instead of url_unescape.

* src/url.c (url_unescape_1): New static function.
(url_unescape): Calls url_unescape_1 with mask zero. Preserves
same behavior as before. Only code changes.
(url_unescape_except_reserved): New function.

* src/url.h: Added prototype for url_unescape_except_reserved().

When the locale is US-ASCII, URIs that contain special characters
in them are converted to IRIs according to RFC 3987, section 3.2
"Converting URIs to IRIs".

src/iri.c

@@ -136,7 +136,7 @@ do_conversion (const char *tocode, const char *fromcode, char const *in_org, siz
 
   /* iconv() has to work on an unescaped string */
   in_save = in = xstrndup (in_org, inlen);
-  url_unescape(in);
+  url_unescape_except_reserved (in);
   inlen = strlen(in);
 
   len = outlen = inlen * 2;

src/url.c

@@ -161,17 +161,8 @@ static const unsigned char urlchr_table[256] =
 #undef U
 #undef RU
 
-/* URL-unescape the string S.
-
-   This is done by transforming the sequences "%HH" to the character
-   represented by the hexadecimal digits HH.  If % is not followed by
-   two hexadecimal digits, it is inserted literally.
-
-   The transformation is done in place.  If you need the original
-   string intact, make a copy before calling this function.  */
-
-void
-url_unescape (char *s)
+static void
+url_unescape_1 (char *s, unsigned char mask)
 {
   char *t = s;                  /* t - tortoise */
   char *h = s;                  /* h - hare     */
@@ -190,6 +181,8 @@ url_unescape (char *s)
           if (!h[1] || !h[2] || !(c_isxdigit (h[1]) && c_isxdigit (h[2])))
             goto copychar;
           c = X2DIGITS_TO_NUM (h[1], h[2]);
+          if (urlchr_test(c, mask))
+            goto copychar;
           /* Don't unescape %00 because there is no way to insert it
              into a C string without effectively truncating it. */
           if (c == '\0')
@@ -201,6 +194,31 @@ url_unescape (char *s)
   *t = '\0';
 }
 
+/* URL-unescape the string S.
+
+   This is done by transforming the sequences "%HH" to the character
+   represented by the hexadecimal digits HH.  If % is not followed by
+   two hexadecimal digits, it is inserted literally.
+
+   The transformation is done in place.  If you need the original
+   string intact, make a copy before calling this function.  */
+void
+url_unescape (char *s)
+{
+  url_unescape_1 (s, 0);
+}
+
+/* URL-unescape the string S.
+
+   This functions behaves identically as url_unescape(), but does not
+   convert characters from "reserved". In other words, it only converts
+   "unsafe" characters.  */
+void
+url_unescape_except_reserved (char *s)
+{
+  url_unescape_1 (s, urlchr_reserved);
+}
+
 /* The core of url_escape_* functions.  Escapes the characters that
    match the provided mask in urlchr_table.
 

src/url.h

@@ -106,6 +106,7 @@ struct url
 char *url_escape (const char *);
 char *url_escape_unsafe_and_reserved (const char *);
 void url_unescape (char *);
+void url_unescape_except_reserved (char *);
 
 struct url *url_parse (const char *, int *, struct iri *iri, bool percent_encode);
 char *url_error (const char *, int);