Add requirements marks on the built-in collating functions.

FossilOrigin-Name: 4b608b62ac8d4eafdb76192b3b5db272332a4bfd

manifest

@@ -1,5 +1,5 @@
-C Ensure\sthat\swhen\sthe\snumber\sof\scells\son\sa\spage\sdrops\sto\szero\sthat\sthe\sfreelist\nand\sfragment\scounter\sare\sboth\scleared.\s\sAlso\sadd\sevidence\smarks\scorresponding\nto\sfile-format\sdocumentation.
-D 2014-11-20T15:30:50.141
+C Add\srequirements\smarks\son\sthe\sbuilt-in\scollating\sfunctions.
+D 2014-11-20T19:22:26.830
 F Makefile.arm-wince-mingw32ce-gcc d6df77f1f48d690bd73162294bbba7f59507c72f
 F Makefile.in a226317fdf3f4c895fb3cfedc355b4d0868ce1fb
 F Makefile.linux-gcc 91d710bdc4998cb015f39edf3cb314ec4f4d7e23
@@ -195,7 +195,7 @@ F src/journal.c b4124532212b6952f42eb2c12fa3c25701d8ba8d
 F src/legacy.c ba1863ea58c4c840335a84ec276fc2b25e22bc4e
 F src/lempar.c 7274c97d24bb46631e504332ccd3bd1b37841770
 F src/loadext.c de741e66e5ddc1598d904d7289239696e40ed994
-F src/main.c d3310d5ed56e246bf1589e47eeaca8be582bd4b8
+F src/main.c 54d0f4896cebc61ae5f831937464953780fe5346
 F src/malloc.c 740db54387204c9a2eb67c6d98e68b08e9ef4eab
 F src/mem0.c 6a55ebe57c46ca1a7d98da93aaa07f99f1059645
 F src/mem1.c faf615aafd8be74a71494dfa027c113ea5c6615f
@@ -1221,7 +1221,7 @@ F tool/vdbe_profile.tcl 67746953071a9f8f2f668b73fe899074e2c6d8c1
 F tool/warnings-clang.sh f6aa929dc20ef1f856af04a730772f59283631d4
 F tool/warnings.sh 0abfd78ceb09b7f7c27c688c8e3fe93268a13b32
 F tool/win/sqlite.vsix deb315d026cc8400325c5863eef847784a219a2f
-P 2d7c8da5f16e64eaa7b0c2d66898682ea3d102a0
-R aa709859c03f6b1c53283cb1512cbe99
+P ef9fbc08b0a047042deeb2d6007d67028fefb9e2
+R 87fc16da633f081b9c3d6138857b30da
 U drh
-Z 12bf55f57cbfdde86aed8c230487a6ad
+Z 4f4a01f4cbeff0ca684ca414f4595d57

manifest.uuid

@@ -1 +1 @@
-ef9fbc08b0a047042deeb2d6007d67028fefb9e2
+4b608b62ac8d4eafdb76192b3b5db272332a4bfd

src/main.c

@@ -773,13 +773,20 @@ static int binCollFunc(
 ){
   int rc, n;
   n = nKey1<nKey2 ? nKey1 : nKey2;
+  /* EVIDENCE-OF: R-65033-28449 The built-in BINARY collation compares
+  ** strings byte by byte using the memcmp() function from the standard C
+  ** library. */
   rc = memcmp(pKey1, pKey2, n);
   if( rc==0 ){
     if( padFlag
      && allSpaces(((char*)pKey1)+n, nKey1-n)
      && allSpaces(((char*)pKey2)+n, nKey2-n)
     ){
-      /* Leave rc unchanged at 0 */
+      /* EVIDENCE-OF: R-31624-24737 RTRIM is like BINARY except that extra
+      ** spaces at the end of either string do not change the result. In other
+      ** words, strings will compare equal to one another as long as they
+      ** differ only in the number of spaces at the end.
+      */
     }else{
       rc = nKey1 - nKey2;
     }
@@ -2730,20 +2737,24 @@ static int openDatabase(
   /* Add the default collation sequence BINARY. BINARY works for both UTF-8
   ** and UTF-16, so add a version for each to avoid any unnecessary
   ** conversions. The only error that can occur here is a malloc() failure.
+  **
+  ** EVIDENCE-OF: R-52786-44878 SQLite defines three built-in collating
+  ** functions:
   */
   createCollation(db, "BINARY", SQLITE_UTF8, 0, binCollFunc, 0);
   createCollation(db, "BINARY", SQLITE_UTF16BE, 0, binCollFunc, 0);
   createCollation(db, "BINARY", SQLITE_UTF16LE, 0, binCollFunc, 0);
+  createCollation(db, "NOCASE", SQLITE_UTF8, 0, nocaseCollatingFunc, 0);
   createCollation(db, "RTRIM", SQLITE_UTF8, (void*)1, binCollFunc, 0);
   if( db->mallocFailed ){
     goto opendb_out;
   }
+  /* EVIDENCE-OF: R-08308-17224 The default collating function for all
+  ** strings is BINARY. 
+  */
   db->pDfltColl = sqlite3FindCollSeq(db, SQLITE_UTF8, "BINARY", 0);
   assert( db->pDfltColl!=0 );
 
-  /* Also add a UTF-8 case-insensitive collation sequence. */
-  createCollation(db, "NOCASE", SQLITE_UTF8, 0, nocaseCollatingFunc, 0);
-
   /* Parse the filename/URI argument. */
   db->openFlags = flags;
   rc = sqlite3ParseUri(zVfs, zFilename, &flags, &db->pVfs, &zOpen, &zErrMsg);