Various small improvements to format detection.

geoPHP.inc

@@ -215,18 +215,27 @@ class geoPHP
 
     $bytes = unpack("c*", fread($mem, 11));
 
+    // If bytes is empty, then we were passed empty input
+    if (empty($bytes)) return FALSE;
+
+    // First char is a tab, space or carriage-return. trim it and try again
+    if ($bytes[1] == 9 || $bytes[1] == 10 || $bytes[1] == 32) {
+      return geoPHP::detectFormat(ltrim($input));
+    }
+
     // Detect WKB or EWKB -- first byte is 1 (little endian indicator)
     if ($bytes[1] == 1) {
       // If SRID byte is TRUE (1), it's EWKB
       if ($bytes[5]) return 'ewkb';
       else return 'wkb';
     }
 
-    // Detect HEX encoded WKB or EWKB -- first byte is 48, second byte is 49 (hex '01' => first-byte = 1)
+    // Detect HEX encoded WKB or EWKB (PostGIS format) -- first byte is 48, second byte is 49 (hex '01' => first-byte = 1)
     if ($bytes[1] == 48 && $bytes[2] == 49) {
-      // The shortest possible WKB string (LINESTRING EMPTY) is 9 bytes long (18 hex chars)
+      // The shortest possible WKB string (LINESTRING EMPTY) is 18 hex-chars (9 encoded bytes) long
+      // This differentiates it from a geohash, which is always shorter than 18 characters.
       if (strlen($input) >= 18) {
-        //@@TODO: Differentiate between EWKB and WKB -- check bytes 10 or 11 (SRID bool indicator)
+        //@@TODO: Differentiate between EWKB and WKB -- check hex-char 10 or 11 (SRID bool indicator at encoded byte 5)
         return 'ewkb:1';
       }
     }