From 44e7f4f0ebc852514a0463a1a1868529336e0fe1 Mon Sep 17 00:00:00 2001
From: Sebastian Pipping <sebastian@pipping.org>
Date: Sat, 29 Mar 2025 02:32:24 +0100
Subject: [PATCH] xmlwf: Address clang-tidy warning
 bugprone-narrowing-conversions

The symptom was:
> [..]/expat/xmlwf/xmlfile.c:204:13: error: narrowing conversion from 'ssize_t' (aka 'long') to signed type 'int' is implementation-defined [bugprone-narrowing-conversions,-warnings-as-errors]
>   204 |     nread = read(fd, buf, g_read_size_bytes);
>       |             ^
> [..]/expat/xmlwf/xmlwf.c:314:14: error: narrowing conversion from 'unsigned long' to signed type 'int' is implementation-defined [bugprone-narrowing-conversions,-warnings-as-errors]
>   314 |   numBytes = count * sizeof(XML_Char);
>       |              ^

The solution to read(3) was copied from file xmlwf/readfilemap.c for now.
---
 expat/xmlwf/xmlfile.c | 19 +++++++++++++------
 expat/xmlwf/xmlwf.c   |  2 +-
 2 files changed, 14 insertions(+), 7 deletions(-)

diff --git a/expat/xmlwf/xmlfile.c b/expat/xmlwf/xmlfile.c
index 9c4f7f8d..78a3a73b 100644
--- a/expat/xmlwf/xmlfile.c
+++ b/expat/xmlwf/xmlfile.c
@@ -56,12 +56,19 @@
 #include "xmltchar.h"
 #include "filemap.h"
 
+/* Function "read": */
 #if defined(_MSC_VER)
 #  include <io.h>
-#endif
-
-#ifdef HAVE_UNISTD_H
+/* https://msdn.microsoft.com/en-us/library/wyssk1bs(v=vs.100).aspx */
+#  define EXPAT_read _read
+#  define EXPAT_read_count_t int
+#  define EXPAT_read_req_t unsigned int
+#else /* POSIX */
 #  include <unistd.h>
+/* https://pubs.opengroup.org/onlinepubs/009695399/functions/read.html */
+#  define EXPAT_read read
+#  define EXPAT_read_count_t ssize_t
+#  define EXPAT_read_req_t size_t
 #endif
 
 #ifndef O_BINARY
@@ -192,7 +199,7 @@ processStream(const XML_Char *filename, XML_Parser parser) {
     }
   }
   for (;;) {
-    int nread;
+    EXPAT_read_count_t nread;
     char *buf = (char *)XML_GetBuffer(parser, g_read_size_bytes);
     if (! buf) {
       if (filename != NULL)
@@ -201,14 +208,14 @@ processStream(const XML_Char *filename, XML_Parser parser) {
                filename != NULL ? filename : T("xmlwf"));
       return 0;
     }
-    nread = read(fd, buf, g_read_size_bytes);
+    nread = EXPAT_read(fd, buf, (EXPAT_read_req_t)g_read_size_bytes);
     if (nread < 0) {
       tperror(filename != NULL ? filename : T("STDIN"));
       if (filename != NULL)
         close(fd);
       return 0;
     }
-    if (XML_ParseBuffer(parser, nread, nread == 0) == XML_STATUS_ERROR) {
+    if (XML_ParseBuffer(parser, (int)nread, nread == 0) == XML_STATUS_ERROR) {
       reportError(parser, filename != NULL ? filename : T("STDIN"));
       if (filename != NULL)
         close(fd);
diff --git a/expat/xmlwf/xmlwf.c b/expat/xmlwf/xmlwf.c
index 7c0a8cd4..ec7e51c9 100644
--- a/expat/xmlwf/xmlwf.c
+++ b/expat/xmlwf/xmlwf.c
@@ -305,7 +305,7 @@ static XML_Char *
 xcsdup(const XML_Char *s) {
   XML_Char *result;
   int count = 0;
-  int numBytes;
+  size_t numBytes;
 
   /* Get the length of the string, including terminator */
   while (s[count++] != 0) {