idn: fix libidn2 with windows unicode builds

Unicode Windows builds use UTF-8 strings internally in libcurl,
so make sure to call the UTF-8 flavour of the libidn2 API. Also
document that Windows builds with libidn2 and UNICODE do expect
CURLOPT_URL as an UTF-8 string.

Reported-by: dEajL3kA on github
Assisted-by: Jay Satiro
Reviewed-by: Marcel Raad
Closes #7246
Fixes #7228

diff --git a/docs/libcurl/opts/CURLOPT_URL.3 b/docs/libcurl/opts/CURLOPT_URL.3
index 17e5c8b8993122d52772d139186f88f08676a1ab..e33d866bf40117c541540d157c5a0dad9a0d2f49 100644 (file)
--- a/docs/libcurl/opts/CURLOPT_URL.3
+++ b/docs/libcurl/opts/CURLOPT_URL.3
@@ -72,7 +72,7 @@ expected to be a sequence of characters using an ASCII compatible encoding.
 
 If libcurl is built with IDN support, the server name part of the URL can use
 an "international name" by using the current encoding (according to locale) or
-UTF-8 (when winidn is used).
+UTF-8 (when winidn is used; or a Windows Unicode build using libidn2).
 
 If libcurl is built without IDN support, the server name is used exactly as
 specified when passed to the name resolver functions.

diff --git a/lib/url.c b/lib/url.c
index e923357724574b00f7a6977f9fe5f8674476ca94..9a96e6a93be645ca3121c7fe76e333be0ce91937 100644 (file)
--- a/lib/url.c
+++ b/lib/url.c
@@ -62,6 +62,14 @@
 #ifdef USE_LIBIDN2
 #include <idn2.h>
 
+#if defined(WIN32) && defined(UNICODE)
+#define IDN2_LOOKUP(name, host, flags) \
+  idn2_lookup_u8((const uint8_t *)name, (uint8_t **)host, flags)
+#else
+#define IDN2_LOOKUP(name, host, flags) \
+  idn2_lookup_ul((const char *)name, (char **)host, flags)
+#endif
+
 #elif defined(USE_WIN32_IDN)
 /* prototype for curl_win32_idn_to_ascii() */
 bool curl_win32_idn_to_ascii(const char *in, char **out);
@@ -1585,12 +1593,12 @@ CURLcode Curl_idnconvert_hostname(struct Curl_easy *data,
 #else
       int flags = IDN2_NFC_INPUT;
 #endif
-      int rc = idn2_lookup_ul((const char *)host->name, &ace_hostname, flags);
+      int rc = IDN2_LOOKUP(host->name, &ace_hostname, flags);
       if(rc != IDN2_OK)
         /* fallback to TR46 Transitional mode for better IDNA2003
            compatibility */
-        rc = idn2_lookup_ul((const char *)host->name, &ace_hostname,
-                            IDN2_TRANSITIONAL);
+        rc = IDN2_LOOKUP(host->name, &ace_hostname,
+                         IDN2_TRANSITIONAL);
       if(rc == IDN2_OK) {
         host->encalloc = (char *)ace_hostname;
         /* change the name pointer to point to the encoded hostname */