diff '-x*~' -pru bash-5.2-alpha/builtins/printf.def bash-5.2-alpha-double/builtins/printf.def
--- bash-5.2-alpha/builtins/printf.def	2021-12-29 13:09:20.000000000 -0800
+++ bash-5.2-alpha-double/builtins/printf.def	2022-04-09 12:02:35.330476097 -0700
@@ -215,13 +215,14 @@ static uintmax_t getuintmax PARAMS((void
 
 #if defined (HAVE_LONG_DOUBLE) && HAVE_DECL_STRTOLD && !defined(STRTOLD_BROKEN)
 typedef long double floatmax_t;
-#  define FLOATMAX_CONV	"L"
+#  define USE_LONG_DOUBLE 1
 #  define strtofltmax	strtold
 #else
 typedef double floatmax_t;
-#  define FLOATMAX_CONV	""
+#  define USE_LONG_DOUBLE 0
 #  define strtofltmax	strtod
 #endif
+static double getdouble PARAMS((void));
 static floatmax_t getfloatmax PARAMS((void));
 
 static intmax_t asciicode PARAMS((void));
@@ -247,7 +248,7 @@ printf_builtin (list)
      WORD_LIST *list;
 {
   int ch, fieldwidth, precision;
-  int have_fieldwidth, have_precision;
+  int have_fieldwidth, have_precision, use_Lmod;
   char convch, thisch, nextch, *format, *modstart, *precstart, *fmt, *start;
 #if defined (HANDLE_MULTIBYTE)
   char mbch[25];		/* 25 > MB_LEN_MAX, plus can handle 4-byte UTF-8 and large Unicode characters*/
@@ -422,8 +423,12 @@ printf_builtin (list)
 
 	  /* skip possible format modifiers */
 	  modstart = fmt;
+	  use_Lmod = 0;
 	  while (*fmt && strchr (LENMODS, *fmt))
-	    fmt++;
+	    {
+	      use_Lmod |= USE_LONG_DOUBLE && *fmt == 'L';
+	      fmt++;
+	    }
 	    
 	  if (*fmt == 0)
 	    {
@@ -694,11 +699,24 @@ printf_builtin (list)
 #endif
 	      {
 		char *f;
-		floatmax_t p;
 
-		p = getfloatmax ();
-		f = mklong (start, FLOATMAX_CONV, sizeof(FLOATMAX_CONV) - 1);
-		PF (f, p);
+		if (use_Lmod)
+		  {
+		    floatmax_t p;
+
+		    p = getfloatmax ();
+		    f = mklong (start, "L", 1);
+		    PF (f, p);
+		  }
+		else
+		  {
+		    double p;
+
+		    p = getdouble ();
+		    f = mklong (start, "", 0);
+		    PF (f, p);
+		  }
+
 		break;
 	      }
 
@@ -1248,35 +1266,40 @@ getuintmax ()
   return (ret);
 }
 
+#define getfloat(ret, convert) \
+  char *ep; \
+  if (garglist == 0) \
+    return 0; \
+  if (garglist->word->word[0] == '\'' || garglist->word->word[0] == '"') \
+    return asciicode (); \
+  errno = 0; \
+  (ret) = (convert) (garglist->word->word, &ep); \
+  if (*ep) \
+    { \
+      sh_invalidnum (garglist->word->word); \
+      /* Same thing about POSIX.2 conversion error requirements. */ \
+      if (0) \
+        (ret) = 0; \
+      conversion_error = 1; \
+    } \
+  else if (errno == ERANGE) \
+    printf_erange (garglist->word->word); \
+  garglist = garglist->next
+
+static double
+getdouble ()
+{
+  double ret;
+  getfloat (ret, strtod);
+  return ret;
+}
+
 static floatmax_t
 getfloatmax ()
 {
   floatmax_t ret;
-  char *ep;
-
-  if (garglist == 0)
-    return (0);
-
-  if (garglist->word->word[0] == '\'' || garglist->word->word[0] == '"')
-    return asciicode ();
-
-  errno = 0;
-  ret = strtofltmax (garglist->word->word, &ep);
-
-  if (*ep)
-    {
-      sh_invalidnum (garglist->word->word);
-#if 0
-      /* Same thing about POSIX.2 conversion error requirements. */
-      ret = 0;
-#endif
-      conversion_error = 1;
-    }
-  else if (errno == ERANGE)
-    printf_erange (garglist->word->word);
-
-  garglist = garglist->next;
-  return (ret);
+  getfloat (ret, strtofltmax);
+  return ret;
 }
 
 /* NO check is needed for garglist here. */
diff '-x*~' -pru bash-5.2-alpha/CHANGES bash-5.2-alpha-double/CHANGES
--- bash-5.2-alpha/CHANGES	2022-01-10 14:22:14.000000000 -0800
+++ bash-5.2-alpha-double/CHANGES	2022-04-09 11:58:36.473880401 -0700
@@ -142,6 +142,9 @@ uu. Fixed a problem with quoting shell e
     they appear in a tab-completed word along with characters that do need
     quoting (e.g.. $HOME/VirtualBox VMs).
 
+vv. The printf builtin now ordinarily uses 'double' for floating point
+    formats like %g.  Use formats like %Lg for 'long double'.
+
 2. Changes to Readline
 
 a. Fixed a problem with cleaning up active marks when using callback mode.