bz2: Fix truncation of total output size causing erroneous errors

Also switch to uint64_t as that's used on master and makes the code
simpler to fix.

Closes GH-20807.

Co-authored-by: Arnaud Le Blanc <arnaud.lb@gmail.com>

NEWS

@@ -2,6 +2,9 @@ PHP                                                                        NEWS
 |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
 ?? ??? ????, PHP 8.4.20
 
+- Bz2:
+  . Fix truncation of total output size causing erroneous errors. (ndossche)
+
 - PCRE:
   . Fixed re-entrancy issue on php_pcre_match_impl, php_pcre_replace_impl,
     php_pcre_split_impl, and php_pcre_grep_impl. (David Carlier)

ext/bz2/bz2.c

@@ -502,11 +502,7 @@ PHP_FUNCTION(bzdecompress)
 	size_t source_len;
 	int error;
 	bool small = 0;
-#ifdef PHP_WIN32
-	unsigned __int64 size = 0;
-#else
-	unsigned long long size = 0;
-#endif
+	uint64_t size = 0;
 	bz_stream bzs;
 
 	if (FAILURE == zend_parse_parameters(ZEND_NUM_ARGS(), "s|b", &source, &source_len, &small)) {
@@ -531,27 +527,22 @@ PHP_FUNCTION(bzdecompress)
 	while ((error = BZ2_bzDecompress(&bzs)) == BZ_OK && bzs.avail_in > 0) {
 		/* compression is better then 2:1, need to allocate more memory */
 		bzs.avail_out = source_len;
-		size = (bzs.total_out_hi32 * (unsigned int) -1) + bzs.total_out_lo32;
-#ifndef ZEND_ENABLE_ZVAL_LONG64
+		size = (((uint64_t) bzs.total_out_hi32) << 32U) + bzs.total_out_lo32;
 		if (size > SIZE_MAX) {
 			/* no reason to continue if we're going to drop it anyway */
 			break;
 		}
-#endif
 		dest = zend_string_safe_realloc(dest, 1, bzs.avail_out+1, (size_t) size, 0);
 		bzs.next_out = ZSTR_VAL(dest) + size;
 	}
 
 	if (error == BZ_STREAM_END || error == BZ_OK) {
-		size = (bzs.total_out_hi32 * (unsigned int) -1) + bzs.total_out_lo32;
-#ifndef ZEND_ENABLE_ZVAL_LONG64
+		size = (((uint64_t) bzs.total_out_hi32) << 32U) + bzs.total_out_lo32;
 		if (UNEXPECTED(size > SIZE_MAX)) {
 			php_error_docref(NULL, E_WARNING, "Decompressed size too big, max is %zd", SIZE_MAX);
 			zend_string_efree(dest);
 			RETVAL_LONG(BZ_MEM_ERROR);
-		} else
-#endif
-		{
+		} else {
 			dest = zend_string_safe_realloc(dest, 1, (size_t)size, 1, 0);
 			ZSTR_LEN(dest) = (size_t)size;
 			ZSTR_VAL(dest)[(size_t)size] = '\0';