Fix bad return or empty string arguments in SolrUtils

Fixes #83
There is no reason for returning null given an empty string.
Plus, the methods don't actually "say" they return null, ever.
Also, escapeQueryChars() actually never returns false.
That will be fixed in documentation.

Author: bix0r

src/php_solr_utils.c

@@ -31,11 +31,6 @@ PHP_METHOD(SolrUtils, escapeQueryChars)
 		RETURN_FALSE;
 	}
 
-	if (!unescaped_length) {
-
-		RETURN_NULL();
-	}
-
 	memset(&sbuilder, 0, sizeof(solr_string_t));
 
 	solr_escape_query_chars(&sbuilder, unescaped, unescaped_length);
@@ -59,11 +54,6 @@ PHP_METHOD(SolrUtils, queryPhrase)
 		RETURN_FALSE;
 	}
 
-	if (!unescaped_length) {
-
-		RETURN_NULL();
-	}
-
 	memset(&sbuilder, 0, sizeof(solr_string_t));
 
 	solr_string_appendc(&sbuilder, '"');

tests/204.solrutils_empty_escapequerychars.phpt

@@ -0,0 +1,10 @@
+--TEST--
+SolrUtils::escapeQueryChars() - Testing empty queryString
+--FILE--
+<?php
+var_dump(SolrUtils::escapeQueryChars(''));
+var_dump(SolrUtils::queryPhrase(''));
+?>
+--EXPECTF--
+string(0) ""
+string(2) """"