diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/func.c | 15 |
1 files changed, 12 insertions, 3 deletions
diff --git a/src/func.c b/src/func.c index 537d35be1..6cb8d5aa9 100644 --- a/src/func.c +++ b/src/func.c @@ -16,7 +16,7 @@ ** sqliteRegisterBuildinFunctions() found at the bottom of the file. ** All other code has file scope. ** -** $Id: func.c,v 1.229 2009/04/02 13:36:37 drh Exp $ +** $Id: func.c,v 1.230 2009/04/02 14:05:22 drh Exp $ */ #include "sqliteInt.h" #include <stdlib.h> @@ -362,8 +362,17 @@ static void randomFunc( sqlite_int64 r; UNUSED_PARAMETER2(NotUsed, NotUsed2); sqlite3_randomness(sizeof(r), &r); - if( (r<<1)==0 ) r = 0; /* Prevent 0x8000.... as the result so that we */ - /* can always do abs() of the result */ + if( r<0 ){ + /* We need to prevent a random number of 0x8000000000000000 + ** (or -9223372036854775808) since when you do abs() of that + ** number of you get the same value back again. To do this + ** in a way that is testable, mask the sign bit off of negative + ** values, resulting in a positive value. Then take the + ** 2s complement of that positive value. The end result can + ** therefore be no less than -9223372036854775807. + */ + r = -(r ^ (((sqlite3_int64)1)<<63)); + } sqlite3_result_int64(context, r); } |