On Android, I see a test failure:
FAIL: test-yesno.sh
===================
test-yesno: write error: Bad address
test-yesno: write error: Bad address
xout.tmp out.tmp differ: char 1, line 1
test-yesno: write error: Bad address
test-yesno: write error: Bad address
xout.tmp out.tmp differ: char 1, line 1
test-yesno: write error: Bad address
cmp: EOF on out.tmp which is empty
FAIL test-yesno.sh (exit status: 1)
The cause is that
- This test uses atexit (close_stdin);
- close_stdin calls fflush (stdin). This uses the Gnulib replacement for
fflush. In function update_fpos_cache it overwrites a word of memory
past *stdin. Namely the first word of *stdout.
- Then, close_stdin calls close_stdout, which calls close_stream (stdout),
which calls __fpending (stdout). Since *stdout is not in a valid state,
__fpending (stdout) returns a huge value, rather than 0.
- close_stream then goes along a wrong control path.
This patch fixes it.
2023-01-17 Bruno Haible <br...@clisp.org>
fflush: Fix a buffer overrun on 32-bit Android.
* lib/stdio-impl.h (fp_): On Android, change the type of _offset to
'long'.
* lib/fflush.c (update_fpos_cache): On Android, update a 'long', not an
'fpos_t'.
diff --git a/lib/fflush.c b/lib/fflush.c
index d38f5f00a3..f3689b3e81 100644
--- a/lib/fflush.c
+++ b/lib/fflush.c
@@ -99,7 +99,7 @@ update_fpos_cache (_GL_ATTRIBUTE_MAYBE_UNUSED FILE *fp,
{
# if defined __sferror || defined __DragonFly__ || defined __ANDROID__
/* FreeBSD, NetBSD, OpenBSD, DragonFly, Mac OS X, Cygwin, Minix 3, Android */
-# if defined __CYGWIN__
+# if defined __CYGWIN__ || defined __ANDROID__
/* fp_->_offset is typed as an integer. */
fp_->_offset = pos;
# else
diff --git a/lib/stdio-impl.h b/lib/stdio-impl.h
index 81e7f83837..89056b0de5 100644
--- a/lib/stdio-impl.h
+++ b/lib/stdio-impl.h
@@ -96,7 +96,7 @@
unsigned char _nbuf[1]; \
struct { unsigned char *_base; size_t _size; } _lb; \
int _blksize; \
- fpos_t _offset; \
+ long _offset; \
/* More fields, not relevant here. */ \
} *) fp)
# else
