Fixed bug #35817 (unpack() does not decode odd number of hexadecimal values)

NEWS

@@ -9,6 +9,8 @@ PHP                                                                        NEWS
   (Andrey)
 - Fixed bug #35821 (array_map() segfaults when exception is throwed from 
   the callback). (Tony)
+- Fixed bug #35817 (unpack() does not decode odd number of hexadecimal values).
+  (Ilia)
 - Fixed bug #35781 (stream_filter_append() can cause segfault). (Tony)
 - Fixed bug #35759 (mysqli_stmt_bind_result() makes huge allocation when
   column empty). (Andrey)

ext/standard/pack.c

@@ -245,7 +245,7 @@ PHP_FUNCTION(pack)
 		switch ((int) code) {
 			case 'h': 
 			case 'H': 
-				INC_OUTPUTPOS((arg + 1) / 2,1)	/* 4 bit per arg */
+				INC_OUTPUTPOS((arg + (arg % 2)) / 2,1)	/* 4 bit per arg */
 				break;
 
 			case 'a': 
@@ -538,7 +538,7 @@ PHP_FUNCTION(unpack)
 	while (formatlen-- > 0) {
 		char type = *(format++);
 		char c;
-		int arg = 1;
+		int arg = 1, argb;
 		char *name;
 		int namelen;
 		int size=0;
@@ -563,6 +563,7 @@ PHP_FUNCTION(unpack)
 
 		/* Get of new value in array */
 		name = format;
+		argb = arg;
 
 		while (formatlen > 0 && *format != '/') {
 			formatlen--;
@@ -592,7 +593,7 @@ PHP_FUNCTION(unpack)
 
 			case 'h': 
 			case 'H': 
-				size = (arg > 0) ? arg / 2 : arg;
+				size = (arg > 0) ? (arg + (arg % 2)) / 2 : arg;
 				arg = 1;
 				break;
 
@@ -691,6 +692,8 @@ PHP_FUNCTION(unpack)
 							len = size * 2;
 						} 
 
+						len -= argb % 2;
+
 						buf = emalloc(len + 1);
 
 						for (ipos = opos = 0; opos < len; opos++) {

ext/standard/tests/strings/bug35817.phpt

@@ -0,0 +1,29 @@
+--TEST--
+Bug #35817 (unpack() does not decode odd number of hexadecimal values)
+--FILE--
+<?php
+$a = pack("H3","181");
+$b = unpack("H3", $a);
+var_dump($b);
+
+$a = pack("H2","18");
+$b = unpack("H2", $a);
+var_dump($b);
+
+$a = pack("H","1");
+$b = unpack("H", $a);
+var_dump($b);
+?>
+--EXPECT--
+array(1) {
+  [1]=>
+  string(3) "181"
+}
+array(1) {
+  [1]=>
+  string(2) "18"
+}
+array(1) {
+  [1]=>
+  string(1) "1"
+}