# Fixes a problem where the size of off_t is miscalculated on certain platforms.

--- a/src/libmpg123/lfs_wrap.c
+++ b/src/libmpg123/lfs_wrap.c
@@ -48,18 +48,22 @@
 #ifndef OFF_MAX
 #undef OFF_MIN
 #if SIZEOF_OFF_T == 4
+#define REAL_SIZEOF_OFF_T 4
 #define OFF_MAX INT32_MAX
 #define OFF_MIN INT32_MIN
-#elif SIZEOF_OFF_T == 8
+#elif SIZEOF_OFF_T == 8 || (defined(__EMSCRIPTEN__) && SIZEOF_OFF_T == 0)
+#define REAL_SIZEOF_OFF_T 8
 #define OFF_MAX INT64_MAX
 #define OFF_MIN INT64_MIN
 #else
 #error "Unexpected width of off_t."
 #endif
+#else
+#define REAL_SIZEOF_OFF_T SIZEOF_OFF_T
 #endif
 
 // A paranoid check that someone did not define a wrong SIZEOF_OFF_T at configure time.
-typedef unsigned char MPG123_STATIC_ASSERT[(SIZEOF_OFF_T == sizeof(off_t)) ? 1 : -1];
+typedef unsigned char MPG123_STATIC_ASSERT[(REAL_SIZEOF_OFF_T == sizeof(off_t)) ? 1 : -1];
 
 #include "../common/debug.h"
 
@@ -87,7 +91,7 @@ int attribute_align_arg mpg123_position64( mpg123_handle *fr, int64_t no, int64_
 struct wrap_data
 {
 	/* Storage for small offset index table. */
-#if SIZEOF_OFF_T == 4
+#if REAL_SIZEOF_OFF_T == 4
 	off_t *indextable;
 	// And ironically, another big offset table for mpg123_set_index_32.
 	// I wand to avoid having to change a line of code in the internals.
@@ -153,7 +157,7 @@ void INT123_wrap_destroy(void *handle)
 	if(!wh)
 		return;
 	wrap_io_cleanup(handle);
-#if SIZEOF_OFF_T == 4
+#if REAL_SIZEOF_OFF_T == 4
 	if(wh->indextable != NULL)
 		free(wh->indextable);
 	if(wh->set_indextable != NULL)
@@ -184,7 +188,7 @@ static struct wrap_data* wrap_get(mpg123_handle *mh, int force_alloc)
 			return NULL;
 		}
 		whd = *whd_;
-#if SIZEOF_OFF_T == 4
+#if REAL_SIZEOF_OFF_T == 4
 		whd->indextable = NULL;
 		whd->set_indextable = NULL;
 #endif
@@ -313,7 +317,7 @@ off_t attribute_align_arg mpg123_length(mpg123_handle *mh)
 // If the former, we create a copy of the index table.
 int attribute_align_arg mpg123_index(mpg123_handle *mh, off_t **offsets, off_t *step, size_t *fill)
 {
-#if SIZEOF_OFF_T == 8
+#if REAL_SIZEOF_OFF_T == 8
 	return mpg123_index64(mh, (int64_t**)offsets, (int64_t*)step, fill);
 #else
 	int err;
@@ -354,7 +358,7 @@ int attribute_align_arg mpg123_index(mpg123_handle *mh, off_t **offsets, off_t *
 
 int attribute_align_arg mpg123_set_index(mpg123_handle *mh, off_t *offsets, off_t step, size_t fill)
 {
-#if SIZEOF_OFF_T == 8
+#if REAL_SIZEOF_OFF_T == 8
 	return mpg123_set_index64(mh, (int64_t*)offsets, (int64_t)step, fill);
 #else
 	int err;
@@ -410,7 +414,7 @@ int attribute_align_arg mpg123_position( mpg123_handle *mh, off_t INT123_frame_o
 
 // _32 aliases only for native 32 bit off_t
 // Will compilers be smart enough to optimize away the extra function call?
-#if SIZEOF_OFF_T == 4
+#if REAL_SIZEOF_OFF_T == 4
 
 // The open routines are trivial now. I only have differeing symbols suffixes
 // to keep legacy ABI.
@@ -524,7 +528,7 @@ int attribute_align_arg mpg123_position_32( mpg123_handle *mh, off_t INT123_fram
 // _64 aliases if we either got some off64_t to work with or
 // if there is no explicit 64 bit API but off_t is just always
 // 64 bits.
-#if defined(LFS_LARGEFILE_64) || (SIZEOF_OFF_T == 8)
+#if defined(LFS_LARGEFILE_64) || (REAL_SIZEOF_OFF_T == 8)
 
 #ifdef LFS_LARGEFILE_64
 #define OFF64 off64_t
@@ -954,7 +958,7 @@ int attribute_align_arg mpg123_replace_reader_handle(mpg123_handle *mh, mpg123_s
 	return MPG123_OK;
 }
 
-#if SIZEOF_OFF_T == 4
+#if REAL_SIZEOF_OFF_T == 4
 int attribute_align_arg mpg123_replace_reader_32(mpg123_handle *mh, mpg123_ssize_t (*r_read) (int, void *, size_t), off_t (*r_lseek)(int, off_t, int) )
 {
 	return mpg123_replace_reader(mh, r_read, r_lseek);
@@ -1019,7 +1023,7 @@ int attribute_align_arg mpg123_replace_reader_handle_64(mpg123_handle *mh, mpg12
 	return MPG123_OK;
 }
 
-#elif SIZEOF_OFF_T == 8
+#elif REAL_SIZEOF_OFF_T == 8
 
 // If 64 bit off_t is enforced, libmpg123.c already defines the _64 functions.
 #ifndef FORCED_OFF_64