From 2bab5d3e730a184468f38fca4aaf93e29a691018 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?M=C3=A5ns=20Rullg=C3=A5rd?= <mans@mansr.com>
Date: Sun, 18 Jul 2010 18:38:23 +0000
Subject: [PATCH] Allow all valid (and only valid) characters in URL scheme for
 url_open()

The URL specification allows letters, numbers, plus, hyphen, and period
in the scheme part.  The isalpha() test would allow additional characters
depending on locale settings while rejecting numbers and punctuation.

Originally committed as revision 24306 to svn://svn.ffmpeg.org/ffmpeg/trunk
---
 libavformat/avio.c | 30 +++++++++++-------------------
 1 file changed, 11 insertions(+), 19 deletions(-)

diff --git a/libavformat/avio.c b/libavformat/avio.c
index 19f0183abd..0e9e887e31 100644
--- a/libavformat/avio.c
+++ b/libavformat/avio.c
@@ -167,29 +167,21 @@ int url_open_protocol (URLContext **puc, struct URLProtocol *up,
     return ret;
 }
 
+#define URL_SCHEME_CHARS                        \
+    "abcdefghijklmnopqrstuvwxyz"                \
+    "ABCDEFGHIJKLMNOPQRSTUVWXYZ"                \
+    "0123456789+-."
+
 int url_alloc(URLContext **puc, const char *filename, int flags)
 {
     URLProtocol *up;
-    const char *p;
-    char proto_str[128], *q;
-
-    p = filename;
-    q = proto_str;
-    while (*p != '\0' && *p != ':') {
-        /* protocols can only contain alphabetic chars */
-        if (!isalpha(*p))
-            goto file_proto;
-        if ((q - proto_str) < sizeof(proto_str) - 1)
-            *q++ = *p;
-        p++;
-    }
-    /* if the protocol has length 1, we consider it is a dos drive */
-    if (*p == '\0' || is_dos_path(filename)) {
-    file_proto:
+    char proto_str[128];
+    size_t proto_len = strspn(filename, URL_SCHEME_CHARS);
+
+    if (filename[proto_len] != ':' || is_dos_path(filename))
         strcpy(proto_str, "file");
-    } else {
-        *q = '\0';
-    }
+    else
+        av_strlcpy(proto_str, filename, FFMIN(proto_len+1, sizeof(proto_str)));
 
     up = first_protocol;
     while (up != NULL) {