Check scheme part in redirected URI more strictly.

The previous implementation mistakenly sees '/abspath?uri=http://foo'
as an absolute URI because it contains '://', but actually it is not.
This change checks scheme part is constructed in the allowed character
set described in RFC 3986 Section 3.1.

src/Request.cc

@@ -114,7 +114,26 @@ bool Request::redirectUri(const std::string& uri) {
     redirectedUri = getProtocol();
     redirectedUri += ":";
     redirectedUri += uri;
-  } else if(uri.find("://") == std::string::npos) {
+  } else {
+    std::string::size_type schemeEnd = uri.find("://");
+    bool absUri;
+    if(schemeEnd == std::string::npos) {
+      absUri = false;
+    } else {
+      absUri = true;
+      // Check that scheme is acceptable one.
+      for(size_t i = 0; i < schemeEnd; ++i) {
+        char c = uri[i];
+        if(!util::isAlpha(c) && !util::isDigit(c) &&
+           c != '+' && c != '-' && c != '.') {
+          absUri = false;
+          break;
+        }
+      }
+    }
+    if(absUri) {
+      redirectedUri = uri;
+    } else {
       // rfc2616 requires absolute URI should be provided by Location header
       // field, but some servers don't obey this rule.
       // UPDATE: draft-ietf-httpbis-p2-semantics-18 now allows this.
@@ -129,8 +148,7 @@ bool Request::redirectUri(const std::string& uri) {
       }
       redirectedUri = uri::construct(rus);
       redirectedUri.append(uri.begin()+offset, uri.end());
-  } else {
+    }
-    redirectedUri = uri;
   }
   return parseUri(redirectedUri);
 }

src/util.h

@@ -358,6 +358,8 @@ bool isNumber(InputIterator first, InputIterator last)
   return true;
 }
 
+bool isAlpha(const char c);
+
 bool isDigit(const char c);
 
 bool isHexDigit(const char c);

test/RequestTest.cc

@@ -142,6 +142,12 @@ void RequestTest::testRedirectUri()
   CPPUNIT_ASSERT(req.redirectUri("//host/to/file"));
   CPPUNIT_ASSERT_EQUAL(std::string("http://host/to/file"), req.getCurrentUri());
   CPPUNIT_ASSERT_EQUAL(5, req.getRedirectCount());
+
+  // http:// in query part
+  CPPUNIT_ASSERT(req.redirectUri("/abspath?uri=http://foo"));
+  CPPUNIT_ASSERT_EQUAL(std::string("http://host/abspath?uri=http://foo"),
+                       req.getCurrentUri());
+  CPPUNIT_ASSERT_EQUAL(6, req.getRedirectCount());
 }
 
 void RequestTest::testRedirectUri2()