Automerge.

configure.in

@@ -838,8 +838,8 @@ AC_TYPE_SIZE_T
 AC_HEADER_DIRENT
 AC_HEADER_STDC
 AC_HEADER_SYS_WAIT
-AC_CHECK_HEADERS(fcntl.h fenv.h float.h floatingpoint.h ieeefp.h limits.h \
- memory.h pwd.h select.h \
+AC_CHECK_HEADERS(fcntl.h fenv.h float.h floatingpoint.h fpu_control.h \
+ ieeefp.h limits.h memory.h pwd.h select.h \
  stdlib.h stddef.h \
  strings.h string.h synch.h sys/mman.h sys/socket.h netinet/in.h arpa/inet.h \
  sys/timeb.h sys/types.h sys/un.h sys/vadvise.h sys/wait.h term.h \

mysql-test/r/explain.result

@@ -238,4 +238,17 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
 2	SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
 DROP TABLE t1, t2;
+#
+# Bug #48573: difference of index selection between rpm binary and
+#             .tar.gz, windows vs linux..
+#
+CREATE TABLE t1(c1 INT, c2 INT, c4 INT, c5 INT, KEY(c2, c5), KEY(c2, c4, c5));
+INSERT INTO t1 VALUES(4, 1, 1, 1);
+INSERT INTO t1 VALUES(3, 1, 1, 1);
+INSERT INTO t1 VALUES(2, 1, 1, 1);
+INSERT INTO t1 VALUES(1, 1, 1, 1);
+EXPLAIN SELECT c1 FROM t1 WHERE c2 = 1 AND c4 = 1 AND c5 = 1;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	t1	ref	c2,c2_2	c2	10	const,const	3	Using where
+DROP TABLE t1;
 End of 5.1 tests.

mysql-test/t/explain.test

@@ -213,4 +213,19 @@ EXPLAIN SELECT 1 FROM t1 WHERE a = (SELECT 1 FROM t1 t JOIN t2 WHERE b <= 1 AND
 
 DROP TABLE t1, t2;
 
+--echo #
+--echo # Bug #48573: difference of index selection between rpm binary and
+--echo #             .tar.gz, windows vs linux..
+--echo #
+
+CREATE TABLE t1(c1 INT, c2 INT, c4 INT, c5 INT, KEY(c2, c5), KEY(c2, c4, c5));
+INSERT INTO t1 VALUES(4, 1, 1, 1);
+INSERT INTO t1 VALUES(3, 1, 1, 1);
+INSERT INTO t1 VALUES(2, 1, 1, 1);
+INSERT INTO t1 VALUES(1, 1, 1, 1);
+
+EXPLAIN SELECT c1 FROM t1 WHERE c2 = 1 AND c4 = 1 AND c5 = 1;
+
+DROP TABLE t1;
+
 --echo End of 5.1 tests.

sql/mysqld.cc

@@ -183,6 +183,21 @@ typedef fp_except fp_except_t;
 /* for IRIX to use set_fpc_csr() */
 #include <sys/fpu.h>
 #endif
+#ifdef HAVE_FPU_CONTROL_H
+#include <fpu_control.h>
+#endif
+#if defined(__i386__) && !defined(HAVE_FPU_CONTROL_H)
+# define fpu_control_t unsigned int
+# define _FPU_EXTENDED 0x300
+# define _FPU_DOUBLE 0x200
+# ifdef __GNUC__
+#  define _FPU_GETCW(cw) __asm__ __volatile__("fnstcw %0" : "=m" (*&cw))
+#  define _FPU_SETCW(cw) __asm__ __volatile__("fldcw %0" : : "m" (*&cw))
+# else
+#  define _FPU_GETCW(cw) (cw= 0)
+#  define _FPU_SETCW(cw)
+# endif
+#endif
 
 inline void setup_fpu()
 {
@@ -205,6 +220,25 @@ inline void setup_fpu()
   fesetround(FE_TONEAREST);
 #endif /* HAVE_FESETROUND */
 
+  /*
+    x86 (32-bit) requires FPU precision to be explicitly set to 64 bit
+    (double precision) for portable results of floating point operations.
+    However, there is no need to do so if compiler is using SSE2 for floating
+    point, double values will be stored and processed in 64 bits anyway.
+  */
+#if defined(__i386__) && !defined(__SSE2_MATH__)
+#if defined(_WIN32)
+#if !defined(_WIN64)
+  _control87(_PC_53, MCW_PC);
+#endif /* !_WIN64 */
+#else /* !_WIN32 */
+  fpu_control_t cw;
+  _FPU_GETCW(cw);
+  cw= (cw & ~_FPU_EXTENDED) | _FPU_DOUBLE;
+  _FPU_SETCW(cw);
+#endif /* _WIN32 && */
+#endif /* __i386__ */
+
 #if defined(__sgi) && defined(HAVE_SYS_FPU_H)
   /* Enable denormalized DOUBLE values support for IRIX */
   union fpc_csr n;