config.c: Tolerate UTF8 BOM at the beginning of config file

diff --git a/config.c b/config.c
index 53f04a076a7275965090edd4ca2a34652c4f5679..1d3012047d7b3c7f2ad1ba6aea4884954b9d4bfe 100644 (file)
--- a/config.c
+++ b/config.c
@@ -205,8 +205,27 @@ static int git_parse_file(config_fn_t fn, void *data)
        int baselen = 0;
        static char var[MAXNAME];
 
+       /* U+FEFF Byte Order Mark in UTF8 */
+       static const unsigned char *utf8_bom = (unsigned char *) "\xef\xbb\xbf";
+       const unsigned char *bomptr = utf8_bom;
+
        for (;;) {
                int c = get_next_char();
+               if (bomptr && *bomptr) {
+                       /* We are at the file beginning; skip UTF8-encoded BOM
+                        * if present. Sane editors won't put this in on their
+                        * own, but e.g. Windows Notepad will do it happily. */
+                       if ((unsigned char) c == *bomptr) {
+                               bomptr++;
+                               continue;
+                       } else {
+                               /* Do not tolerate partial BOM. */
+                               if (bomptr != utf8_bom)
+                                       break;
+                               /* No BOM at file beginning. Cool. */
+                               bomptr = NULL;
+                       }
+               }
                if (c == '\n') {
                        if (config_file_eof)
                                return 0;