fix for fdflags loadable builtin; new strptime loadable builtin; enable -f doesn't fall back to current directory if using BASH_LOADABLES_PATH; new operator for rl_complete_internal that just dumps possible completions

lib/malloc/malloc.c

@@ -997,10 +997,13 @@ internal_free (PTR_T mem, const char *file, int line, int flags)
 #if defined (USE_MMAP)
   if (nunits > malloc_mmap_threshold)
     {
+      int o;
+      o = errno;
       munmap (p, binsize (nunits));
 #if defined (MALLOC_STATS)
       _mstats.nlesscore[nunits]++;
 #endif
+      errno = o;		/* POSIX says free preserves errno */
       goto free_return;
     }
 #endif
@@ -1015,7 +1018,10 @@ internal_free (PTR_T mem, const char *file, int line, int flags)
 	 there's already a block on the free list. */
       if ((nunits >= LESSCORE_FRC) || busy[nunits] || nextf[nunits] != 0)
 	{
+	  int o;
+	  o = errno;
 	  lesscore (nunits);
+	  errno = o;
 	  /* keeps the tracing and registering code in one place */
 	  goto free_return;
 	}

lib/malloc/sbrk.c

@@ -0,0 +1,80 @@
+/* Copyright (C) 2023 Free Software Foundation, Inc.
+
+   This file is part of GNU Bash, the Bourne Again SHell.
+
+   Bash is free software: you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation, either version 3 of the License, or
+   (at your option) any later version.
+
+   Bash is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with Bash.  If not, see <http://www.gnu.org/licenses/>.
+*/
+#include <config.h>
+#include <unistd.h>
+#include <errno.h>
+
+#if defined (HAVE_BRK) && !defined (HAVE_SBRK)
+
+static void *initialbrk;
+static void *curbrk;
+
+static int
+brkinit (void)
+{
+  if (initialbrk == 0)
+    {
+      void *b;
+
+      b = brk (NULL);
+      if (b == (void *)-1)
+	return -1;
+      initialbrk = curbrk = b;
+    }
+  return (0);
+}
+
+/* sbrk(3) implementation in terms of brk(2). Good enough for malloc to use. */
+void *
+sbrk (intptr_t incr)
+{
+  void *newbrk, *oldbrk;
+
+  if (initialbrk == 0 && initbrk () == -1)
+    {
+      errno = ENOMEM;
+      return (void *)-1;
+    }
+
+  if (incr == 0)
+    return curbrk;
+
+  /* bounds checking, overflow */
+  if ((incr > 0 && (uintptr_t) curbrk + incr < (uintptr_t) curbrk) ||
+      (incr < 0 && (uintptr_t) curbrk + incr > (uintptr_t) curbrk))
+    {
+      errno = ENOMEM;
+      return (void *)-1;
+    }
+
+  newbrk = curbrk + incr;  
+  if (newbrk < initialbrk)
+    {
+      errno = EINVAL;
+      return (void *)-1;
+    }
+
+  if (brk (newbrk) == (void *)-1)
+    return (void *)-1;		/* preserve errno */
+
+  oldbrk = curbrk;
+  curbrk = newbrk;
+
+  return (oldbrk);
+}
+#endif /* HAVE_BRK && !HAVE_SBRK */