1 files changed, 20 insertions, 4 deletions
diff --git a/skate/url.go b/skate/url.go
index f81b1d2..b59103f 100644
--- a/skate/url.go
+++ b/skate/url.go
@@ -12,8 +12,22 @@ var (
 	patHttpDOI             = regexp.MustCompile(`(https?:\/\/)(10[.][0-9]{1,8}\/.*)`)
 	patAccessedOn          = regexp.MustCompile(`(?iU)(.*)[.;,]?(abgerufen|acces-sed|últimoacesso|updated|ac-cessed|zugegriffen|diunduh|adresinden|sayfasındanulaşıl|accessedon|consultéle|consultad|diaksestanggal|diaksespadatanggal|diakses|dateofaccess|lastaccessed|acesso|acessado|accessoem|accessed|recibido|accessedat|доступ-свободный|датаобращения|pageconsulté|indirme|downloadedfrom).*$`)
 	patFileExtraSuffix     = regexp.MustCompile(`(?i)(http.*[.](pdf\+html|zip|pdf|html|doc|docx|rar))([^?]*)$`)
+	patBrokenHttpSchema    = regexp.MustCompile(`^https?[^://]*?.*`)
+	patBrokenSchemaPrefix  = regexp.MustCompile(`(http|https)\W+(.*)`)
+
+	okSchemas = []string{"http://", "https://", "ftp://"}
 )
 
+// hasAnyPrefixes returns true, if any of the prefixes matches string s.
+func hasAnyPrefix(s string, prefix []string) bool {
+	for _, p := range prefix {
+		if strings.HasPrefix(s, p) {
+			return true
+		}
+	}
+	return false
+}
+
 // SanitizeURL applies various cleanup rules on URLs as found in references.
 // Returns an empty string when no URL could be constructed. Still, many
 // results will not be a URL after all.  XXX: Sometimes a URL contains other
@@ -21,7 +35,7 @@ var (
 // http://agingmind.utdallas.edu/facedb/view/neutral-faces.doi:10.3758/BF03206543.
 // http://10.3386/w20634https://doi.org/10.3386/w20634
 func SanitizeURL(s string) string {
-	if !strings.HasPrefix(s, "http") && !strings.HasPrefix(s, "ftp") {
+	if !hasAnyPrefix(s, okSchemas) {
 		s = sanitizeRaw(s)
 		if s == "" {
 			return s
@@ -70,10 +84,12 @@ func sanitizeRaw(s string) string {
 	}
 	indices := index.Lookup([]byte("www."), 1)
 	if len(indices) > 0 {
-		s = "http://" + s[indices[0]:]
-	} else {
-		s = "http://" + s
+		return "http://" + s[indices[0]:]
+	}
+	if patBrokenSchemaPrefix.MatchString(s) {
+		return patBrokenSchemaPrefix.ReplaceAllString(s, `http://$2`)
 	}
+	s = "http://" + s
 	return s
 	// Re-trievedfrom
 }