* lib/xprintf.c (xprintf, xfprintf): Test err < 0, not just "err".

[gnulib.git] / lib / md5.c

diff --git a/lib/md5.c b/lib/md5.c
index 87db8f9..917a899 100644 (file)
--- a/lib/md5.c
+++ b/lib/md5.c
@@ -1,8 +1,8 @@
-/* md5.c - Functions to compute MD5 message digest of files or memory blocks
+/* Functions to compute MD5 message digest of files or memory blocks.

    according to the definition of MD5 in RFC 1321 from April 1992.
    according to the definition of MD5 in RFC 1321 from April 1992.

-   Copyright (C) 1995, 1996, 2001, 2003, 2004, 2005 Free Software Foundation, Inc.
-   NOTE: The canonical source of this file is maintained with the GNU C
-   Library.  Bugs can be reported to bug-glibc@prep.ai.mit.edu.
+   Copyright (C) 1995,1996,1997,1999,2000,2001,2005,2006
+       Free Software Foundation, Inc.
+   This file is part of the GNU C Library.

 
    This program is free software; you can redistribute it and/or modify it
    under the terms of the GNU General Public License as published by the
 
    This program is free software; you can redistribute it and/or modify it
    under the terms of the GNU General Public License as published by the


@@ -20,14 +20,14 @@
 
 /* Written by Ulrich Drepper <drepper@gnu.ai.mit.edu>, 1995.  */
 
 
 /* Written by Ulrich Drepper <drepper@gnu.ai.mit.edu>, 1995.  */
 

-#ifdef HAVE_CONFIG_H
-# include <config.h>
-#endif
+#include <config.h>

 
 #include "md5.h"
 
 #include <stddef.h>
 
 #include "md5.h"
 
 #include <stddef.h>

+#include <stdlib.h>

 #include <string.h>
 #include <string.h>

+#include <sys/types.h>

 
 #if USE_UNLOCKED_IO
 # include "unlocked-io.h"
 
 #if USE_UNLOCKED_IO
 # include "unlocked-io.h"


@@ -84,14 +84,14 @@ md5_init_ctx (struct md5_ctx *ctx)
    must be in little endian byte order.
 
    IMPORTANT: On some systems it is required that RESBUF is correctly
    must be in little endian byte order.
 
    IMPORTANT: On some systems it is required that RESBUF is correctly

-   aligned for a 32 bits value.  */
+   aligned for a 32-bit value.  */

 void *
 md5_read_ctx (const struct md5_ctx *ctx, void *resbuf)
 {
 void *
 md5_read_ctx (const struct md5_ctx *ctx, void *resbuf)
 {

-  ((md5_uint32 *) resbuf)[0] = SWAP (ctx->A);
-  ((md5_uint32 *) resbuf)[1] = SWAP (ctx->B);
-  ((md5_uint32 *) resbuf)[2] = SWAP (ctx->C);
-  ((md5_uint32 *) resbuf)[3] = SWAP (ctx->D);
+  ((uint32_t *) resbuf)[0] = SWAP (ctx->A);
+  ((uint32_t *) resbuf)[1] = SWAP (ctx->B);
+  ((uint32_t *) resbuf)[2] = SWAP (ctx->C);
+  ((uint32_t *) resbuf)[3] = SWAP (ctx->D);

 
   return resbuf;
 }
 
   return resbuf;
 }


@@ -100,29 +100,27 @@ md5_read_ctx (const struct md5_ctx *ctx, void *resbuf)
    prolog according to the standard and write the result to RESBUF.
 
    IMPORTANT: On some systems it is required that RESBUF is correctly
    prolog according to the standard and write the result to RESBUF.
 
    IMPORTANT: On some systems it is required that RESBUF is correctly

-   aligned for a 32 bits value.  */
+   aligned for a 32-bit value.  */

 void *
 md5_finish_ctx (struct md5_ctx *ctx, void *resbuf)
 {
   /* Take yet unprocessed bytes into account.  */
 void *
 md5_finish_ctx (struct md5_ctx *ctx, void *resbuf)
 {
   /* Take yet unprocessed bytes into account.  */

-  md5_uint32 bytes = ctx->buflen;
-  size_t pad;
+  uint32_t bytes = ctx->buflen;
+  size_t size = (bytes < 56) ? 64 / 4 : 64 * 2 / 4;

 
   /* Now count remaining bytes.  */
   ctx->total[0] += bytes;
   if (ctx->total[0] < bytes)
     ++ctx->total[1];
 
 
   /* Now count remaining bytes.  */
   ctx->total[0] += bytes;
   if (ctx->total[0] < bytes)
     ++ctx->total[1];
 

-  pad = bytes >= 56 ? 64 + 56 - bytes : 56 - bytes;
-  memcpy (&ctx->buffer[bytes], fillbuf, pad);
-

   /* Put the 64-bit file length in *bits* at the end of the buffer.  */
   /* Put the 64-bit file length in *bits* at the end of the buffer.  */

-  *(md5_uint32 *) &ctx->buffer[bytes + pad] = SWAP (ctx->total[0] << 3);
-  *(md5_uint32 *) &ctx->buffer[bytes + pad + 4] = SWAP ((ctx->total[1] << 3) |
-                                                       (ctx->total[0] >> 29));
+  ctx->buffer[size - 2] = SWAP (ctx->total[0] << 3);
+  ctx->buffer[size - 1] = SWAP ((ctx->total[1] << 3) | (ctx->total[0] >> 29));
+
+  memcpy (&((char *) ctx->buffer)[bytes], fillbuf, (size - 2) * 4 - bytes);

 
   /* Process last bytes.  */
 
   /* Process last bytes.  */

-  md5_process_block (ctx->buffer, bytes + pad + 8, ctx);
+  md5_process_block (ctx->buffer, size * 4, ctx);

 
   return md5_read_ctx (ctx, resbuf);
 }
 
   return md5_read_ctx (ctx, resbuf);
 }


@@ -144,8 +142,8 @@ md5_stream (FILE *stream, void *resblock)
   while (1)
     {
       /* We read the file in blocks of BLOCKSIZE bytes.  One call of the
   while (1)
     {
       /* We read the file in blocks of BLOCKSIZE bytes.  One call of the

-        computation function processes the whole buffer so that with the
-        next round of the loop another block can be read.  */
+         computation function processes the whole buffer so that with the
+         next round of the loop another block can be read.  */

       size_t n;
       sum = 0;
 
       size_t n;
       sum = 0;
 


@@ -162,8 +160,8 @@ md5_stream (FILE *stream, void *resblock)
          if (n == 0)
            {
              /* Check for the error flag IFF N == 0, so that we don't
          if (n == 0)
            {
              /* Check for the error flag IFF N == 0, so that we don't

-                exit the loop after a partial read due to e.g., EAGAIN
-                or EWOULDBLOCK.  */
+                exit the loop after a partial read due to e.g., EAGAIN
+                or EWOULDBLOCK.  */

              if (ferror (stream))
                return 1;
              goto process_partial_block;
              if (ferror (stream))
                return 1;
              goto process_partial_block;


@@ -177,12 +175,12 @@ md5_stream (FILE *stream, void *resblock)
        }
 
       /* Process buffer with BLOCKSIZE bytes.  Note that
        }
 
       /* Process buffer with BLOCKSIZE bytes.  Note that

-                       BLOCKSIZE % 64 == 0
+         BLOCKSIZE % 64 == 0

        */
       md5_process_block (buffer, BLOCKSIZE, &ctx);
     }
 
        */
       md5_process_block (buffer, BLOCKSIZE, &ctx);
     }
 

- process_partial_block:;
+process_partial_block:

 
   /* Process any remaining bytes.  */
   if (sum > 0)
 
   /* Process any remaining bytes.  */
   if (sum > 0)


@@ -223,7 +221,7 @@ md5_process_bytes (const void *buffer, size_t len, struct md5_ctx *ctx)
       size_t left_over = ctx->buflen;
       size_t add = 128 - left_over > len ? len : 128 - left_over;
 
       size_t left_over = ctx->buflen;
       size_t add = 128 - left_over > len ? len : 128 - left_over;
 

-      memcpy (&ctx->buffer[left_over], buffer, add);
+      memcpy (&((char *) ctx->buffer)[left_over], buffer, add);

       ctx->buflen += add;
 
       if (ctx->buflen > 64)
       ctx->buflen += add;
 
       if (ctx->buflen > 64)


@@ -232,7 +230,8 @@ md5_process_bytes (const void *buffer, size_t len, struct md5_ctx *ctx)
 
          ctx->buflen &= 63;
          /* The regions in the following copy operation cannot overlap.  */
 
          ctx->buflen &= 63;
          /* The regions in the following copy operation cannot overlap.  */

-         memcpy (ctx->buffer, &ctx->buffer[(left_over + add) & ~63],
+         memcpy (ctx->buffer,
+                 &((char *) ctx->buffer)[(left_over + add) & ~63],

                  ctx->buflen);
        }
 
                  ctx->buflen);
        }
 


@@ -245,7 +244,7 @@ md5_process_bytes (const void *buffer, size_t len, struct md5_ctx *ctx)
     {
 #if !_STRING_ARCH_unaligned
 # define alignof(type) offsetof (struct { char c; type x; }, x)
     {
 #if !_STRING_ARCH_unaligned
 # define alignof(type) offsetof (struct { char c; type x; }, x)

-# define UNALIGNED_P(p) (((size_t) p) % alignof (md5_uint32) != 0)
+# define UNALIGNED_P(p) (((size_t) p) % alignof (uint32_t) != 0)

       if (UNALIGNED_P (buffer))
        while (len > 64)
          {
       if (UNALIGNED_P (buffer))
        while (len > 64)
          {


@@ -267,13 +266,13 @@ md5_process_bytes (const void *buffer, size_t len, struct md5_ctx *ctx)
     {
       size_t left_over = ctx->buflen;
 
     {
       size_t left_over = ctx->buflen;
 

-      memcpy (&ctx->buffer[left_over], buffer, len);
+      memcpy (&((char *) ctx->buffer)[left_over], buffer, len);

       left_over += len;
       if (left_over >= 64)
        {
          md5_process_block (ctx->buffer, 64, ctx);
          left_over -= 64;
       left_over += len;
       if (left_over >= 64)
        {
          md5_process_block (ctx->buffer, 64, ctx);
          left_over -= 64;

-         memcpy (ctx->buffer, &ctx->buffer[64], left_over);
+         memcpy (ctx->buffer, &ctx->buffer[16], left_over);

        }
       ctx->buflen = left_over;
     }
        }
       ctx->buflen = left_over;
     }


@@ -295,14 +294,14 @@ md5_process_bytes (const void *buffer, size_t len, struct md5_ctx *ctx)
 void
 md5_process_block (const void *buffer, size_t len, struct md5_ctx *ctx)
 {
 void
 md5_process_block (const void *buffer, size_t len, struct md5_ctx *ctx)
 {

-  md5_uint32 correct_words[16];
-  const md5_uint32 *words = buffer;
-  size_t nwords = len / sizeof (md5_uint32);
-  const md5_uint32 *endp = words + nwords;
-  md5_uint32 A = ctx->A;
-  md5_uint32 B = ctx->B;
-  md5_uint32 C = ctx->C;
-  md5_uint32 D = ctx->D;
+  uint32_t correct_words[16];
+  const uint32_t *words = buffer;
+  size_t nwords = len / sizeof (uint32_t);
+  const uint32_t *endp = words + nwords;
+  uint32_t A = ctx->A;
+  uint32_t B = ctx->B;
+  uint32_t C = ctx->C;
+  uint32_t D = ctx->D;

 
   /* First increment the byte count.  RFC 1321 specifies the possible
      length of the file up to 2^64 bits.  Here we only compute the
 
   /* First increment the byte count.  RFC 1321 specifies the possible
      length of the file up to 2^64 bits.  Here we only compute the


@@ -315,18 +314,18 @@ md5_process_block (const void *buffer, size_t len, struct md5_ctx *ctx)
      the loop.  */
   while (words < endp)
     {
      the loop.  */
   while (words < endp)
     {

-      md5_uint32 *cwp = correct_words;
-      md5_uint32 A_save = A;
-      md5_uint32 B_save = B;
-      md5_uint32 C_save = C;
-      md5_uint32 D_save = D;
+      uint32_t *cwp = correct_words;
+      uint32_t A_save = A;
+      uint32_t B_save = B;
+      uint32_t C_save = C;
+      uint32_t D_save = D;

 
       /* First round: using the given function, the context and a constant
 
       /* First round: using the given function, the context and a constant

-        the next context is computed.  Because the algorithms processing
-        unit is a 32-bit word and it is determined to work on words in
-        little endian byte order we perhaps have to change the byte order
-        before the computation.  To reduce the work for the next steps
-        we store the swapped words in the array CORRECT_WORDS.  */
+         the next context is computed.  Because the algorithms processing
+         unit is a 32-bit word and it is determined to work on words in
+         little endian byte order we perhaps have to change the byte order
+         before the computation.  To reduce the work for the next steps
+         we store the swapped words in the array CORRECT_WORDS.  */

 
 #define OP(a, b, c, d, s, T)                                           \
       do                                                               \
 
 #define OP(a, b, c, d, s, T)                                           \
       do                                                               \


@@ -339,40 +338,40 @@ md5_process_block (const void *buffer, size_t len, struct md5_ctx *ctx)
       while (0)
 
       /* It is unfortunate that C does not provide an operator for
       while (0)
 
       /* It is unfortunate that C does not provide an operator for

-        cyclic rotation.  Hope the C compiler is smart enough.  */
+         cyclic rotation.  Hope the C compiler is smart enough.  */

 #define CYCLIC(w, s) (w = (w << s) | (w >> (32 - s)))
 
       /* Before we start, one word to the strange constants.
 #define CYCLIC(w, s) (w = (w << s) | (w >> (32 - s)))
 
       /* Before we start, one word to the strange constants.

-        They are defined in RFC 1321 as
+         They are defined in RFC 1321 as

 
 

-        T[i] = (int) (4294967296.0 * fabs (sin (i))), i=1..64
+         T[i] = (int) (4294967296.0 * fabs (sin (i))), i=1..64

 
 

-        Here is an equivalent invocation using Perl:
+         Here is an equivalent invocation using Perl:

 
 

-        perl -e 'foreach(1..64){printf "0x%08x\n", int (4294967296 * abs (sin $_))}'
+         perl -e 'foreach(1..64){printf "0x%08x\n", int (4294967296 * abs (sin $_))}'

        */
 
       /* Round 1.  */
        */
 
       /* Round 1.  */

-      OP (A, B, C, D,  7, 0xd76aa478);
+      OP (A, B, C, D, 7, 0xd76aa478);

       OP (D, A, B, C, 12, 0xe8c7b756);
       OP (C, D, A, B, 17, 0x242070db);
       OP (B, C, D, A, 22, 0xc1bdceee);
       OP (D, A, B, C, 12, 0xe8c7b756);
       OP (C, D, A, B, 17, 0x242070db);
       OP (B, C, D, A, 22, 0xc1bdceee);

-      OP (A, B, C, D,  7, 0xf57c0faf);
+      OP (A, B, C, D, 7, 0xf57c0faf);

       OP (D, A, B, C, 12, 0x4787c62a);
       OP (C, D, A, B, 17, 0xa8304613);
       OP (B, C, D, A, 22, 0xfd469501);
       OP (D, A, B, C, 12, 0x4787c62a);
       OP (C, D, A, B, 17, 0xa8304613);
       OP (B, C, D, A, 22, 0xfd469501);

-      OP (A, B, C, D,  7, 0x698098d8);
+      OP (A, B, C, D, 7, 0x698098d8);

       OP (D, A, B, C, 12, 0x8b44f7af);
       OP (C, D, A, B, 17, 0xffff5bb1);
       OP (B, C, D, A, 22, 0x895cd7be);
       OP (D, A, B, C, 12, 0x8b44f7af);
       OP (C, D, A, B, 17, 0xffff5bb1);
       OP (B, C, D, A, 22, 0x895cd7be);

-      OP (A, B, C, D,  7, 0x6b901122);
+      OP (A, B, C, D, 7, 0x6b901122);

       OP (D, A, B, C, 12, 0xfd987193);
       OP (C, D, A, B, 17, 0xa679438e);
       OP (B, C, D, A, 22, 0x49b40821);
 
       /* For the second to fourth round we have the possibly swapped words
       OP (D, A, B, C, 12, 0xfd987193);
       OP (C, D, A, B, 17, 0xa679438e);
       OP (B, C, D, A, 22, 0x49b40821);
 
       /* For the second to fourth round we have the possibly swapped words

-        in CORRECT_WORDS.  Redefine the macro to take an additional first
-        argument specifying the function to use.  */
+         in CORRECT_WORDS.  Redefine the macro to take an additional first
+         argument specifying the function to use.  */

 #undef OP
 #define OP(f, a, b, c, d, k, s, T)                                     \
       do                                                               \
 #undef OP
 #define OP(f, a, b, c, d, k, s, T)                                     \
       do                                                               \


@@ -384,58 +383,58 @@ md5_process_block (const void *buffer, size_t len, struct md5_ctx *ctx)
       while (0)
 
       /* Round 2.  */
       while (0)
 
       /* Round 2.  */

-      OP (FG, A, B, C, D,  1,  5, 0xf61e2562);
-      OP (FG, D, A, B, C,  6,  9, 0xc040b340);
+      OP (FG, A, B, C, D, 1, 5, 0xf61e2562);
+      OP (FG, D, A, B, C, 6, 9, 0xc040b340);

       OP (FG, C, D, A, B, 11, 14, 0x265e5a51);
       OP (FG, C, D, A, B, 11, 14, 0x265e5a51);

-      OP (FG, B, C, D, A,  0, 20, 0xe9b6c7aa);
-      OP (FG, A, B, C, D,  5,  5, 0xd62f105d);
-      OP (FG, D, A, B, C, 10,  9, 0x02441453);
+      OP (FG, B, C, D, A, 0, 20, 0xe9b6c7aa);
+      OP (FG, A, B, C, D, 5, 5, 0xd62f105d);
+      OP (FG, D, A, B, C, 10, 9, 0x02441453);

       OP (FG, C, D, A, B, 15, 14, 0xd8a1e681);
       OP (FG, C, D, A, B, 15, 14, 0xd8a1e681);

-      OP (FG, B, C, D, A,  4, 20, 0xe7d3fbc8);
-      OP (FG, A, B, C, D,  9,  5, 0x21e1cde6);
-      OP (FG, D, A, B, C, 14,  9, 0xc33707d6);
-      OP (FG, C, D, A, B,  3, 14, 0xf4d50d87);
-      OP (FG, B, C, D, A,  8, 20, 0x455a14ed);
-      OP (FG, A, B, C, D, 13,  5, 0xa9e3e905);
-      OP (FG, D, A, B, C,  2,  9, 0xfcefa3f8);
-      OP (FG, C, D, A, B,  7, 14, 0x676f02d9);
+      OP (FG, B, C, D, A, 4, 20, 0xe7d3fbc8);
+      OP (FG, A, B, C, D, 9, 5, 0x21e1cde6);
+      OP (FG, D, A, B, C, 14, 9, 0xc33707d6);
+      OP (FG, C, D, A, B, 3, 14, 0xf4d50d87);
+      OP (FG, B, C, D, A, 8, 20, 0x455a14ed);
+      OP (FG, A, B, C, D, 13, 5, 0xa9e3e905);
+      OP (FG, D, A, B, C, 2, 9, 0xfcefa3f8);
+      OP (FG, C, D, A, B, 7, 14, 0x676f02d9);

       OP (FG, B, C, D, A, 12, 20, 0x8d2a4c8a);
 
       /* Round 3.  */
       OP (FG, B, C, D, A, 12, 20, 0x8d2a4c8a);
 
       /* Round 3.  */

-      OP (FH, A, B, C, D,  5,  4, 0xfffa3942);
-      OP (FH, D, A, B, C,  8, 11, 0x8771f681);
+      OP (FH, A, B, C, D, 5, 4, 0xfffa3942);
+      OP (FH, D, A, B, C, 8, 11, 0x8771f681);

       OP (FH, C, D, A, B, 11, 16, 0x6d9d6122);
       OP (FH, B, C, D, A, 14, 23, 0xfde5380c);
       OP (FH, C, D, A, B, 11, 16, 0x6d9d6122);
       OP (FH, B, C, D, A, 14, 23, 0xfde5380c);

-      OP (FH, A, B, C, D,  1,  4, 0xa4beea44);
-      OP (FH, D, A, B, C,  4, 11, 0x4bdecfa9);
-      OP (FH, C, D, A, B,  7, 16, 0xf6bb4b60);
+      OP (FH, A, B, C, D, 1, 4, 0xa4beea44);
+      OP (FH, D, A, B, C, 4, 11, 0x4bdecfa9);
+      OP (FH, C, D, A, B, 7, 16, 0xf6bb4b60);

       OP (FH, B, C, D, A, 10, 23, 0xbebfbc70);
       OP (FH, B, C, D, A, 10, 23, 0xbebfbc70);

-      OP (FH, A, B, C, D, 13,  4, 0x289b7ec6);
-      OP (FH, D, A, B, C,  0, 11, 0xeaa127fa);
-      OP (FH, C, D, A, B,  3, 16, 0xd4ef3085);
-      OP (FH, B, C, D, A,  6, 23, 0x04881d05);
-      OP (FH, A, B, C, D,  9,  4, 0xd9d4d039);
+      OP (FH, A, B, C, D, 13, 4, 0x289b7ec6);
+      OP (FH, D, A, B, C, 0, 11, 0xeaa127fa);
+      OP (FH, C, D, A, B, 3, 16, 0xd4ef3085);
+      OP (FH, B, C, D, A, 6, 23, 0x04881d05);
+      OP (FH, A, B, C, D, 9, 4, 0xd9d4d039);

       OP (FH, D, A, B, C, 12, 11, 0xe6db99e5);
       OP (FH, C, D, A, B, 15, 16, 0x1fa27cf8);
       OP (FH, D, A, B, C, 12, 11, 0xe6db99e5);
       OP (FH, C, D, A, B, 15, 16, 0x1fa27cf8);

-      OP (FH, B, C, D, A,  2, 23, 0xc4ac5665);
+      OP (FH, B, C, D, A, 2, 23, 0xc4ac5665);

 
       /* Round 4.  */
 
       /* Round 4.  */

-      OP (FI, A, B, C, D,  0,  6, 0xf4292244);
-      OP (FI, D, A, B, C,  7, 10, 0x432aff97);
+      OP (FI, A, B, C, D, 0, 6, 0xf4292244);
+      OP (FI, D, A, B, C, 7, 10, 0x432aff97);

       OP (FI, C, D, A, B, 14, 15, 0xab9423a7);
       OP (FI, C, D, A, B, 14, 15, 0xab9423a7);

-      OP (FI, B, C, D, A,  5, 21, 0xfc93a039);
-      OP (FI, A, B, C, D, 12,  6, 0x655b59c3);
-      OP (FI, D, A, B, C,  3, 10, 0x8f0ccc92);
+      OP (FI, B, C, D, A, 5, 21, 0xfc93a039);
+      OP (FI, A, B, C, D, 12, 6, 0x655b59c3);
+      OP (FI, D, A, B, C, 3, 10, 0x8f0ccc92);

       OP (FI, C, D, A, B, 10, 15, 0xffeff47d);
       OP (FI, C, D, A, B, 10, 15, 0xffeff47d);

-      OP (FI, B, C, D, A,  1, 21, 0x85845dd1);
-      OP (FI, A, B, C, D,  8,  6, 0x6fa87e4f);
+      OP (FI, B, C, D, A, 1, 21, 0x85845dd1);
+      OP (FI, A, B, C, D, 8, 6, 0x6fa87e4f);

       OP (FI, D, A, B, C, 15, 10, 0xfe2ce6e0);
       OP (FI, D, A, B, C, 15, 10, 0xfe2ce6e0);

-      OP (FI, C, D, A, B,  6, 15, 0xa3014314);
+      OP (FI, C, D, A, B, 6, 15, 0xa3014314);

       OP (FI, B, C, D, A, 13, 21, 0x4e0811a1);
       OP (FI, B, C, D, A, 13, 21, 0x4e0811a1);

-      OP (FI, A, B, C, D,  4,  6, 0xf7537e82);
+      OP (FI, A, B, C, D, 4, 6, 0xf7537e82);

       OP (FI, D, A, B, C, 11, 10, 0xbd3af235);
       OP (FI, D, A, B, C, 11, 10, 0xbd3af235);

-      OP (FI, C, D, A, B,  2, 15, 0x2ad7d2bb);
-      OP (FI, B, C, D, A,  9, 21, 0xeb86d391);
+      OP (FI, C, D, A, B, 2, 15, 0x2ad7d2bb);
+      OP (FI, B, C, D, A, 9, 21, 0xeb86d391);

 
       /* Add the starting values of the context.  */
       A += A_save;
 
       /* Add the starting values of the context.  */
       A += A_save;