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authorMichael Gran <spk121@yahoo.com>2023-06-20 16:04:59 -0700
committerMichael Gran <spk121@yahoo.com>2025-03-23 10:26:40 -0700
commitaf96820e072d18c49ac03e80c6f3466d568dc77d (patch)
tree8a4ac5114a091cb2f54f845aabf613b2ef45ac76
parentadbf2156ab5939e6909e035017995ba555886dc2 (diff)
downloadguile-main.tar.gz
Windows 11: for fport input from the console, ignore terminal returnsHEADmain
There is an apparent bug in Windows 11 (not Windows 10) where, when reading from an fd backed by the Console, a single return character will always be available. * libguile/posix-w32.c (console_has_return_keyevent_w32): new procedure * libguile/posix-w32.h: declare console_has_return_keyevent_w32 * libguile/fports.c [__MINGW32__](fport_input_waiting): ignore return keyevent
-rw-r--r--libguile/fports.c15
-rw-r--r--libguile/posix-w32.c48
-rw-r--r--libguile/posix-w32.h1
3 files changed, 63 insertions, 1 deletions
diff --git a/libguile/fports.c b/libguile/fports.c
index e355c3358..51c5b3736 100644
--- a/libguile/fports.c
+++ b/libguile/fports.c
@@ -59,6 +59,9 @@
#include "pairs.h"
#include "ports-internal.h"
#include "posix.h"
+#ifdef __MINGW32__
+# include "posix-w32.h"
+#endif
#include "read.h"
#include "strings.h"
#include "symbols.h"
@@ -483,7 +486,17 @@ fport_input_waiting (SCM port)
if (poll (&pollfd, 1, 0) < 0)
scm_syserror ("fport_input_waiting");
- return pollfd.revents & POLLIN ? 1 : 0;
+ if ((pollfd.revents & POLLIN) == 0)
+ return 0;
+
+#ifdef __MINGW32__
+ /* Work around Windows 11 bug where there's always a return character
+ * in the console input queue. */
+ if (console_has_return_keyevent_w32 (fdes))
+ return 0;
+#endif
+
+ return 1;
}
diff --git a/libguile/posix-w32.c b/libguile/posix-w32.c
index 5f6c0b759..239fd1156 100644
--- a/libguile/posix-w32.c
+++ b/libguile/posix-w32.c
@@ -289,6 +289,54 @@ dlerror_w32 ()
snprintf (dlerror_str, DLERROR_LEN, "error %ld: %s", (long) dw, msg_buf);
return dlerror_str;
}
+
+/* Check for the Windows 11 bug where there's a return character in the
+ * console input queue despite draining the input. */
+int
+console_has_return_keyevent_w32 (int fdes)
+{
+ HANDLE h;
+ DWORD mode;
+
+ h = (HANDLE) _get_osfhandle (fdes);
+ if (h == -1)
+ return 0;
+ if (GetConsoleMode (h, &mode) == 0)
+ return 0;
+
+ // Rarely need more than 1 INPUT_RECORD for this test, but just in
+ // case there is a mouse event in the queue.
+#define NBUFFER 8
+ INPUT_RECORD irbuffer[NBUFFER];
+ BOOL bRet;
+ DWORD avail;
+ int i;
+ int n_chars = 0;
+ int n_returns = 0;
+
+ while (1)
+ {
+ bRet = PeekConsoleInput (h, irbuffer, NBUFFER, &avail);
+ if (!bRet || avail == 0)
+ break;
+
+ for (i = 0; i < avail; i++)
+ if (irbuffer[i].EventType == KEY_EVENT)
+ {
+ n_chars ++;
+ if (irbuffer[i].Event.KeyEvent.uChar.AsciiChar == 13)
+ n_returns ++;
+ }
+ if (avail < NBUFFER)
+ break;
+ }
+
+ if (n_chars == 1 && n_returns == 1)
+ return 1;
+ return 0;
+#undef NBUFFER
+}
+
int
getpagesize_w32 (void)
{
diff --git a/libguile/posix-w32.h b/libguile/posix-w32.h
index a3c27f6f9..5478f91f7 100644
--- a/libguile/posix-w32.h
+++ b/libguile/posix-w32.h
@@ -74,6 +74,7 @@ SCM_INTERNAL void *dlopen_w32 (const char *name, int flags);
SCM_INTERNAL void *dlsym_w32 (void *handle, const char *name);
SCM_INTERNAL int dlclose_w32 (void *handle);
SCM_INTERNAL char *dlerror_w32 (void);
+SCM_INTERNAL int console_has_return_keyevent_w32 (int fdes);
SCM_INTERNAL int getpagesize_w32 (void);
#define HAVE_UNAME 1