--- /dev/null
+++ Libc/Libc-1583.0.14/tests/stdio.c
@@ -0,0 +1,147 @@
+#include <stdio.h>
+#include <err.h>
+#include <errno.h>
+#include <unistd.h>
+#include <sys/resource.h>
+#include <stdlib.h>
+#include <sys/sysctl.h>
+
+#include <darwintest.h>
+
+#define FILE_LIMIT 100
+
+/*
+ * Validate:
+ * (1) the maximum number of fds allowed open per process
+ * implemented by the kernel matches what sysconf expects:
+ *  32 bit: OPEN_MAX
+ *  64 bit: RLIM_INFINITY
+ * (2) fopen does not fail when NOFILE is unlimited.
+ */
+T_DECL(stdio_PR_63187147_SC_STREAM_MAX, "_SC_STREAM_MAX test")
+{
+	struct rlimit rlim;
+	long stream_max, saved_stream_max, open_count, i;
+	int maxfilesperproc, err;
+	size_t maxfilesperproc_size = sizeof(maxfilesperproc);
+	FILE **fp = NULL;
+	const char *filename = "fopen_test";
+
+	T_SETUPBEGIN;
+
+	saved_stream_max = sysconf(_SC_STREAM_MAX);
+	T_LOG("Initial stream_max %ld", saved_stream_max);
+
+	/* Decide the maximum number of fds allowed by the kernel */
+	err = sysctlbyname("kern.maxfilesperproc", &maxfilesperproc, &maxfilesperproc_size, NULL, 0);
+	T_EXPECT_POSIX_SUCCESS(err, "sysctlbyname(\"kern.maxfilesperproc\") returned %d", err);
+	T_LOG("kern.maxfilesperproc %d", maxfilesperproc);
+
+	/*
+	 * Raise RLIMIT_NOFILE to RLIM_INFINITY, note that this does NOT update
+	 * __stream_max in findfp.c
+	 */
+	err = getrlimit(RLIMIT_NOFILE, &rlim);
+	T_EXPECT_POSIX_SUCCESS(err, "getrlimit(RLIMIT_NOFILE)");
+	T_LOG("Initial RLIMIT_NOFILE rlim.cur: 0x%llx", rlim.rlim_cur);
+	rlim.rlim_cur = RLIM_INFINITY;
+	err = setrlimit(RLIMIT_NOFILE, &rlim);
+	T_EXPECT_POSIX_SUCCESS(err, "setrlimit(RLIMIT_NOFILE) to RLIM_INFINITY");
+	err = getrlimit(RLIMIT_NOFILE, &rlim);
+	T_EXPECT_POSIX_SUCCESS(err, "New RLIMIT_NOFILE rlim_cur: 0x%llx", rlim.rlim_cur);
+
+	T_SETUPEND;
+
+	/*
+	 * Test 1 (sysconf with _SC_STREAM_MAX): the largest value sysconf
+	 * returns for _SC_STREAM_MAX is OPEN_MAX (32 bit) or
+	 * RLIM_INFINITY (64 bit)
+	 */
+	stream_max = sysconf(_SC_STREAM_MAX);
+	T_EXPECT_NE_LONG((long)-1, stream_max, "stream_max %ld", stream_max);
+#if __LP64__
+	T_EXPECT_EQ((long)RLIM_INFINITY, stream_max, "sysconf returned 0x%lx", stream_max);
+#else
+	T_EXPECT_EQ((long)OPEN_MAX, stream_max, "sysconf returned 0x%lx", stream_max);
+#endif
+
+	/*
+	 * Test 2 (__stream_max in findfp.c): exercise __sfp by calling fopen
+	 * saved_stream_max + 1 times. Note that we call fopen() up to
+	 * maxfilesperproc times in case fopen() goes nuts.
+	 */
+	fp = malloc(sizeof(FILE *) * (size_t)maxfilesperproc);
+	T_EXPECT_NOTNULL(fp, "Allocated %d FILE pointers", maxfilesperproc);
+	for (i = 0; i < saved_stream_max + 1 && i < maxfilesperproc; i++) {
+	    if (i == saved_stream_max) {
+		T_LOG("The very next fopen should trigger __sfp to update __stream_max and fopen shouldn't fail ");
+	    }
+	    fp[i] = fopen(filename, "r");
+	    T_QUIET; T_EXPECT_NOTNULL(fp, "%ld: fopen(%s, \"r\")", i, filename);
+	}
+	open_count = i;
+
+	for (i = 0; i < open_count; i++) {
+	    fclose(fp[i]);
+	}
+	free(fp);
+
+	T_LOG("saved_stream_max %ld stream_max %ld fopen %ld files", saved_stream_max, stream_max, open_count);
+}
+
+T_DECL(stdio_PR_22813396, "STREAM_MAX is affected by changes to RLIMIT_NOFILE")
+{
+	struct rlimit theLimit;
+	getrlimit( RLIMIT_NOFILE, &theLimit );
+	theLimit.rlim_cur = FILE_LIMIT;
+	setrlimit( RLIMIT_NOFILE, &theLimit );
+
+	long stream_max = sysconf(_SC_STREAM_MAX);
+	T_EXPECT_EQ_LONG(stream_max, (long)FILE_LIMIT, "stream_max = FILE_LIMIT");
+
+	FILE *f;
+	for(int i = 3; i < stream_max; i++) {
+		if((f = fdopen(0, "r")) == NULL) {
+			T_FAIL("Failed after %d streams", i);
+		}
+	}
+
+	f = fdopen(0, "r");
+	T_EXPECT_NULL(f, "fdopen fail after stream_max streams");
+
+	theLimit.rlim_cur = FILE_LIMIT + 1;
+	setrlimit( RLIMIT_NOFILE, &theLimit );
+
+	f = fdopen(0, "r");
+	T_EXPECT_NOTNULL(f, "fdopen succeed after RLIMIT_NOFILE increased");
+}
+
+T_DECL(stdio_PR_22813396_close, "STREAM_MAX is enforced properly after fclose")
+{
+	struct rlimit theLimit;
+	getrlimit( RLIMIT_NOFILE, &theLimit );
+	theLimit.rlim_cur = FILE_LIMIT;
+	setrlimit( RLIMIT_NOFILE, &theLimit );
+
+	long stream_max = sysconf(_SC_STREAM_MAX);
+	T_EXPECT_EQ_LONG(stream_max, (long)FILE_LIMIT, "stream_max = FILE_LIMIT");
+
+	FILE *f;
+	for(int i = 3; i < stream_max - 1; i++) {
+		if((f = fdopen(0, "r")) == NULL) {
+			T_FAIL("Failed after %d streams", i);
+		}
+	}
+
+	// the last stream is for dup(0), it needs to be fclose'd
+	FILE *dupf = NULL;
+	T_EXPECT_NOTNULL(dupf = fdopen(dup(0), "r"), NULL);
+
+	T_EXPECT_NULL(f = fdopen(0, "r"), "fdopen fail after stream_max streams");
+
+	T_EXPECT_POSIX_ZERO(fclose(dupf), "fclose succeeds");
+
+	f = fdopen(0, "r");
+	T_WITH_ERRNO; T_EXPECT_NOTNULL(f, "fdopen succeed after fclose");
+}
+