Add evidence marks for the abs() and soundex() SQL functions.

FossilOrigin-Name: 003f3ed10cdb64b73d6df00e28260dd3491e1f16

manifest

@@ -1,8 +1,8 @@
 -----BEGIN PGP SIGNED MESSAGE-----
 Hash: SHA1
 
-C Version\s3.6.21\srelease\scandidate\s3.
-D 2009-12-07T16:39:13
+C Add\sevidence\smarks\sfor\sthe\sabs()\sand\ssoundex()\sSQL\sfunctions.
+D 2009-12-08T02:06:09
 F Makefile.arm-wince-mingw32ce-gcc fcd5e9cd67fe88836360bb4f9ef4cb7f8e2fb5a0
 F Makefile.in c5827ead754ab32b9585487177c93bb00b9497b3
 F Makefile.linux-gcc d53183f4aa6a9192d249731c90dbdffbd2c68654
@@ -122,7 +122,7 @@ F src/delete.c 8b8afb9cd7783d573eae55a3f4208bc0637a2bb8
 F src/expr.c 50385ed51f1cd7f1ab289629cd0f87d5b2fcca52
 F src/fault.c 160a0c015b6c2629d3899ed2daf63d75754a32bb
 F src/fkey.c e2116672a6bd610dc888e27df292ebc7999c9bb0
-F src/func.c bf54e1202cbfb28bf4b1fd9b58899009ae76716f
+F src/func.c 69906340991919b4933dd8630774ad069e4d582e
 F src/global.c 75946a4a2ab41c6ae58f10ca0ed31b3449694b26
 F src/hash.c 458488dcc159c301b8e7686280ab209f1fb915af
 F src/hash.h 2894c932d84d9f892d4b4023a75e501f83050970
@@ -779,14 +779,14 @@ F tool/speedtest2.tcl ee2149167303ba8e95af97873c575c3e0fab58ff
 F tool/speedtest8.c 2902c46588c40b55661e471d7a86e4dd71a18224
 F tool/speedtest8inst1.c 293327bc76823f473684d589a8160bde1f52c14e
 F tool/vdbe-compress.tcl d70ea6d8a19e3571d7ab8c9b75cba86d1173ff0f
-P cd50acf37fd1e3b388f98fb2df7ed03cff454b24
-R 5d0b6a47a50c8a9cdc60d3d4d61a8cf2
+P 1ed88e9d01e9eda5cbc622e7614277f29bcc551c
+R 1471112a6091b5e86e8377c98442f269
 U drh
-Z 8b76b0c0726e570aef93558fa0c3fdc7
+Z 934fa2af6e75ab66dd516648026804d0
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manifest.uuid

@@ -1 +1 @@
-1ed88e9d01e9eda5cbc622e7614277f29bcc551c
+003f3ed10cdb64b73d6df00e28260dd3491e1f16

src/func.c

@@ -117,7 +117,10 @@ static void lengthFunc(
 }
 
 /*
-** Implementation of the abs() function
+** Implementation of the abs() function.
+**
+** IMP: R-23979-26855 The abs(X) function returns the absolute value of
+** the numeric argument X. 
 */
 static void absFunc(sqlite3_context *context, int argc, sqlite3_value **argv){
   assert( argc==1 );
@@ -127,6 +130,9 @@ static void absFunc(sqlite3_context *context, int argc, sqlite3_value **argv){
       i64 iVal = sqlite3_value_int64(argv[0]);
       if( iVal<0 ){
         if( (iVal<<1)==0 ){
+          /* IMP: R-35460-15084 If X is the integer -9223372036854775807 then
+          ** abs(X) throws an integer overflow error since there is no
+          ** equivalent positive 64-bit two complement value. */
           sqlite3_result_error(context, "integer overflow", -1);
           return;
         }
@@ -136,10 +142,16 @@ static void absFunc(sqlite3_context *context, int argc, sqlite3_value **argv){
       break;
     }
     case SQLITE_NULL: {
+      /* IMP: R-37434-19929 Abs(X) returns NULL if X is NULL. */
       sqlite3_result_null(context);
       break;
     }
     default: {
+      /* Because sqlite3_value_double() returns 0.0 if the argument is not
+      ** something that can be converted into a number, we have:
+      ** IMP: R-57326-31541 Abs(X) return 0.0 if X is a string or blob that
+      ** cannot be converted to a numeric value. 
+      */
       double rVal = sqlite3_value_double(argv[0]);
       if( rVal<0 ) rVal = -rVal;
       sqlite3_result_double(context, rVal);
@@ -1041,9 +1053,16 @@ static void trimFunc(
 }
 
 
+/* IMP: R-25361-16150 This function is omitted from SQLite by default. It
+** is only available if the SQLITE_SOUNDEX compile-time option is used
+** when SQLite is built.
+*/
 #ifdef SQLITE_SOUNDEX
 /*
 ** Compute the soundex encoding of a word.
+**
+** IMP: R-59782-00072 The soundex(X) function returns a string that is the
+** soundex encoding of the string X. 
 */
 static void soundexFunc(
   sqlite3_context *context,
@@ -1087,10 +1106,12 @@ static void soundexFunc(
     zResult[j] = 0;
     sqlite3_result_text(context, zResult, 4, SQLITE_TRANSIENT);
   }else{
+    /* IMP: R-64894-50321 The string "?000" is returned if the argument
+    ** is NULL or contains no ASCII alphabetic characters. */
     sqlite3_result_text(context, "?000", 4, SQLITE_STATIC);
   }
 }
-#endif
+#endif /* SQLITE_SOUNDEX */
 
 #ifndef SQLITE_OMIT_LOAD_EXTENSION
 /*