Add src files for CoreLibs composer all package

src/Convert/MimeEncode.php

@@ -0,0 +1,71 @@
+<?php
+
+/*
+ * alternate for header mime encode to void problems with long strings and
+ * spaces/strange encoding problems.
+ * Orignal issues during PHP5/7
+ */
+
+declare(strict_types=1);
+
+namespace CoreLibs\Convert;
+
+class MimeEncode
+{
+	/**
+	 * wrapper function for mb mime convert
+	 * for correct conversion with long strings
+	 *
+	 * @param  string $string     string to encode
+	 * @param  string $encoding   target encoding
+	 * @param  string $line_break default line break is \r\n
+	 * @return string             encoded string
+	 */
+	public static function __mbMimeEncode(
+		string $string,
+		string $encoding,
+		string $line_break = "\r\n"
+	): string {
+		$current_internal_encoding = mb_internal_encoding();
+		// set internal encoding, so the mimeheader encode works correctly
+		mb_internal_encoding($encoding);
+		// if a subject, make a work around for the broken mb_mimencode
+		$pos = 0;
+		// after 36 single bytes characters,
+		// if then comes MB, it is broken
+		// has to 2 x 36 < 74 so the mb_encode_mimeheader
+		// 74 hardcoded split does not get triggered
+		$split = 36;
+		$_string = '';
+		while ($pos < mb_strlen($string, $encoding)) {
+			$output = mb_strimwidth($string, $pos, $split, "", $encoding);
+			$pos += mb_strlen($output, $encoding);
+			// if the strinlen is 0 here, get out of the loop
+			if (!mb_strlen($output, $encoding)) {
+				$pos += mb_strlen($string, $encoding);
+			}
+			$_string_encoded = mb_encode_mimeheader($output, $encoding);
+			// only make linebreaks if we have mime encoded code inside
+			// the space only belongs in the second line
+			if ($_string && preg_match("/^=\?/", $_string_encoded)) {
+				$_string .= $line_break . " ";
+			} elseif (
+				// hack for plain text with space at the end
+				mb_strlen($output, $encoding) == $split &&
+				mb_substr($output, -1, 1, $encoding) == " "
+			) {
+				// if output ends with space, add one more
+				$_string_encoded .= " ";
+			}
+			$_string .= $_string_encoded;
+		}
+		// strip out any spaces BEFORE a line break
+		$string = str_replace(" " . $line_break, $line_break, $_string);
+		// before we end, reset internal encoding
+		mb_internal_encoding($current_internal_encoding);
+		// return mime encoded string
+		return $string;
+	}
+}
+
+// __END__