Rewrite code to emit BOM. Correct code to determine byte order of

input and convert accordingly.

diff --git a/iconvdata/utf-16.c b/iconvdata/utf-16.c
index 55540c9..c7e677e 100644 (file)
--- a/iconvdata/utf-16.c
+++ b/iconvdata/utf-16.c
@@ -27,6 +27,8 @@
 
 /* This is the Byte Order Mark character (BOM).  */
 #define BOM    0xfeff
+/* And in the other byte order.  */
+#define BOM_OE 0xfffe
 
 
 /* Definitions used in the body of the `gconv' function.  */
@@ -41,8 +43,27 @@
 #define PREPARE_LOOP \
   enum direction dir = ((struct utf16_data *) step->__data)->dir;            \
   enum variant var = ((struct utf16_data *) step->__data)->var;                      \
-  if (!FROM_DIRECTION && var == UTF_16 && !data->__internal_use                      \
-      && data->__invocation_counter == 0)                                    \
+  int swap = ((struct utf16_data *) step->__data)->swap;                     \
+  if (FROM_DIRECTION || var == UTF_16)                                       \
+    {                                                                        \
+      if (data->__invocation_counter == 0)                                   \
+       {                                                                     \
+         /* We have to find out which byte order the file is encoded in.  */ \
+         if (inptr + 2 > inbufend)                                           \
+           return __GCONV_EMPTY_INPUT;                                       \
+                                                                             \
+         if (*(uint16_t *) inptr == BOM)                                     \
+           /* Simply ignore the BOM character.  */                           \
+           inptr += 2;                                                       \
+         else if (*(uint16_t *) inptr == BOM_OE)                             \
+           {                                                                 \
+             ((struct utf16_data *) step->__data)->swap = 1;                 \
+             inptr += 2;                                                     \
+           }                                                                 \
+       }                                                                     \
+    }                                                                        \
+  else if (!FROM_DIRECTION && var == UTF_16 && !data->__internal_use         \
+          && data->__invocation_counter == 0)                                \
     {                                                                        \
       /* Emit the Byte Order Mark.  */                                       \
       if (outbuf + 2 > outend)                                               \
@@ -51,7 +72,7 @@
       *(uint16_t *) outbuf = BOM;                                            \
       outbuf += 2;                                                           \
     }
-#define EXTRA_LOOP_ARGS                , var, data
+#define EXTRA_LOOP_ARGS                , var, data, swap
 
 
 /* Direction of the transformation.  */
@@ -74,6 +95,7 @@ struct utf16_data
 {
   enum direction dir;
   enum variant var;
+  int swap;
 };
 
 
@@ -127,6 +149,9 @@ gconv_init (struct __gconv_step *step)
        {
          new_data->dir = dir;
          new_data->var = var;
+         new_data->swap = ((var == UTF_16LE && BYTE_ORDER == BIG_ENDIAN)
+                           || (var == UTF_16BE
+                               && BYTE_ORDER == LITTLE_ENDIAN));
          step->__data = new_data;
 
          if (dir == from_utf16)
@@ -170,8 +195,7 @@ gconv_end (struct __gconv_step *data)
   {                                                                          \
     uint32_t c = *((uint32_t *) inptr);                                              \
                                                                              \
-    if ((__BYTE_ORDER == __LITTLE_ENDIAN && var == UTF_16BE)                 \
-        || (__BYTE_ORDER == __BIG_ENDIAN && var == UTF_16LE))                \
+    if (swap)                                                                \
       {                                                                              \
        if (c >= 0x10000)                                                     \
          {                                                                   \
@@ -225,7 +249,7 @@ gconv_end (struct __gconv_step *data)
     inptr += 4;                                                                      \
   }
 #define EXTRA_LOOP_DECLS \
-       , enum variant var, struct __gconv_step_data *step_data
+       , enum variant var, struct __gconv_step_data *step_data, int swap
 #include <iconv/loop.c>
 
 
@@ -238,8 +262,7 @@ gconv_end (struct __gconv_step *data)
   {                                                                          \
     uint16_t u1 = *(uint16_t *) inptr;                                       \
                                                                              \
-    if ((__BYTE_ORDER == __LITTLE_ENDIAN && var == UTF_16BE)                 \
-        || (__BYTE_ORDER == __BIG_ENDIAN && var == UTF_16LE))                \
+    if (swap)                                                                \
       {                                                                              \
        u1 = bswap_16 (u1);                                                   \
                                                                              \
@@ -277,16 +300,6 @@ gconv_end (struct __gconv_step *data)
       }                                                                              \
     else                                                                     \
       {                                                                              \
-       if (u1 == BOM && var == UTF_16 && !step_data->__internal_use          \
-           && step_data->__invocation_counter == 0 && inptr == *inptrp)      \
-         {                                                                   \
-           /* This is the first word in the file and it is the BOM and       \
-              we are converting a file without specified byte order.         \
-              Simply sack the BOM.  */                                       \
-           inptr += 2;                                                       \
-           continue;                                                         \
-         }                                                                   \
-                                                                             \
        if (u1 < 0xd800 || u1 > 0xdfff)                                       \
          {                                                                   \
            /* No surrogate.  */                                              \
@@ -322,7 +335,7 @@ gconv_end (struct __gconv_step *data)
     outptr += 4;                                                             \
   }
 #define EXTRA_LOOP_DECLS \
-       , enum variant var, struct __gconv_step_data *step_data
+       , enum variant var, struct __gconv_step_data *step_data, int swap
 #include <iconv/loop.c>