configfile: fix EOF handling

Currently we can end up passing EOF to isspace(), which is in fact
libgit's sane_isspace which does:

	((sane_ctype[(unsigned char)(x)] & (GIT_SPACE)) != 0)

It is very unlikely that EOF cast to "unsigned char" will end up in a
character that has the GIT_SPACE bit set, but the standard only requires
that EOF be a negative integer, so it could access any value in the
sane_ctype array.

If it does end up returning true for isspace() then this loop will never
terminate, so handle EOF as a special value in the same way as the other
loops in this function.

Signed-off-by: John Keeping <john@keeping.me.uk>

diff --git a/configfile.c b/configfile.c
index 5b0d880cb7d2d1da755b2f4bc621a6c460ef4df0..e0391091e147891ca2639142a7b29180030db125 100644 (file)
--- a/configfile.c
+++ b/configfile.c
@@ -39,7 +39,9 @@ static int read_config_line(FILE *f, struct strbuf *name, struct strbuf *value)
 
        /* Skip comments and preceding spaces. */
        for(;;) {
-               if (c == '#' || c == ';')
+               if (c == EOF)
+                       return 0;
+               else if (c == '#' || c == ';')
                        skip_line(f);
                else if (!isspace(c))
                        break;