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Diffstat (limited to 'libio/bug-ungetc3.c')
-rw-r--r--libio/bug-ungetc3.c94
1 files changed, 94 insertions, 0 deletions
diff --git a/libio/bug-ungetc3.c b/libio/bug-ungetc3.c
new file mode 100644
index 0000000..0c83c11
--- /dev/null
+++ b/libio/bug-ungetc3.c
@@ -0,0 +1,94 @@
+/* Test program for ungetc/ftell interaction bug. */
+
+#include <stdio.h>
+
+static void do_prepare (void);
+#define PREPARE(argc, argv) do_prepare ()
+static int do_test (void);
+#define TEST_FUNCTION do_test ()
+#include "../test-skeleton.c"
+
+static const char pattern[] = "12345";
+static char *temp_file;
+
+static void
+do_prepare (void)
+{
+ int fd = create_temp_file ("bug-ungetc.", &temp_file);
+ if (fd == -1)
+ {
+ printf ("cannot create temporary file: %m\n");
+ exit (1);
+ }
+ write (fd, pattern, sizeof (pattern));
+ close (fd);
+}
+
+static int
+do_one_test (int mode)
+{
+ FILE *f;
+
+ f = fopen (temp_file, "r");
+ if (f == NULL)
+ {
+ printf ("could not open temporary file: %m\n");
+ return 1;
+ }
+
+ if (mode == 1 && ftell (f) != 0)
+ {
+ printf ("first ftell returned wrong position %ld\n", ftell (f));
+ return 1;
+ }
+
+ if (fgetc (f) != '1' || fgetc (f) != '2')
+ {
+ puts ("fgetc failed");
+ return 1;
+ }
+
+ if (mode == 2 && ftell (f) != 2)
+ {
+ printf ("second ftell returned wrong position %ld\n", ftell (f));
+ return 1;
+ }
+
+ if (ungetc ('6', f) != '6')
+ {
+ puts ("ungetc failed");
+ return 1;
+ }
+
+ if (ftell (f) != 1)
+ {
+ printf ("third ftell returned wrong position %ld\n", ftell (f));
+ return 1;
+ }
+
+ if (fgetc (f) != '6')
+ {
+ puts ("fgetc failed");
+ return 1;
+ }
+
+ if (ftell (f) != 2)
+ {
+ printf ("fourth ftell returned wrong position %ld\n", ftell (f));
+ return 1;
+ }
+
+ fclose (f);
+
+ return 0;
+}
+
+static int
+do_test (void)
+{
+ int mode;
+ for (mode = 0; mode <= 2; mode++)
+ if (do_one_test (mode))
+ return 1;
+ return 0;
+}