Tweaks to comments in btree.c. Minor code changes to enhance testability.

FossilOrigin-Name: c7d9aa3a1ce63e27ec94295601bc89fecf1e4977

manifest

@@ -1,5 +1,5 @@
-C Fix\sthe\s%c\sformat\scharacter\sin\ssqlite3VXPrintf()\sso\sthat\sit\scorrectly\nhandles\sprecisions\slarger\sthan\s70.
+C Tweaks\sto\scomments\sin\sbtree.c.\s\sMinor\scode\schanges\sto\senhance\stestability.
-D 2014-10-29T18:20:18.932
+D 2014-10-30T20:48:44.305
 F Makefile.arm-wince-mingw32ce-gcc d6df77f1f48d690bd73162294bbba7f59507c72f
 F Makefile.in cf57f673d77606ab0f2d9627ca52a9ba1464146a
 F Makefile.linux-gcc 91d710bdc4998cb015f39edf3cb314ec4f4d7e23
@@ -172,7 +172,7 @@ F src/auth.c b56c78ebe40a2110fd361379f7e8162d23f92240
 F src/backup.c 7f841396adfd47507ff670a471162d2bfcda3136
 F src/bitvec.c 19a4ba637bd85f8f63fc8c9bae5ade9fb05ec1cb
 F src/btmutex.c 49ca66250c7dfa844a4d4cb8272b87420d27d3a5
-F src/btree.c 5189881ca403938c5ceddde496b984fef9f40c5a
+F src/btree.c 8d955d8ef15dd724ea5ef1cb65c17151beaff1e0
 F src/btree.h a79aa6a71e7f1055f01052b7f821bd1c2dce95c8
 F src/btreeInt.h 026d0129724e8f265fdc60d44ec240cf5a4e6179
 F src/build.c 67bb05b1077e0cdaccb2e36bfcbe7a5df9ed31e8
@@ -1209,7 +1209,7 @@ F tool/vdbe_profile.tcl 67746953071a9f8f2f668b73fe899074e2c6d8c1
 F tool/warnings-clang.sh f6aa929dc20ef1f856af04a730772f59283631d4
 F tool/warnings.sh 0abfd78ceb09b7f7c27c688c8e3fe93268a13b32
 F tool/win/sqlite.vsix deb315d026cc8400325c5863eef847784a219a2f
-P 24780f8ddc1683fc62180e6961dc6bfe1168f4df
+P 08a27440f19b7fc884464832e6105af1bf008172
-R c12283d048765bdbe52bad70443f70c1
+R 984c5e022c7b2ce03eb5bed97ff43b89
 U drh
-Z 8aeb3112f50d033e0580c4400e41dd66
+Z 333c45d7dfd79a88b32c00dfbc4028a5

manifest.uuid

@@ -1 +1 @@
-08a27440f19b7fc884464832e6105af1bf008172
+c7d9aa3a1ce63e27ec94295601bc89fecf1e4977

src/btree.c

@@ -1231,10 +1231,8 @@ static int defragmentPage(MemPage *pPage){
 **
 ** If no suitable space can be found on the free-list, return NULL.
 **
-** This function may detect corruption within pPg. If it does and argument 
+** This function may detect corruption within pPg.  If corruption is
-** pRc is non-NULL, then *pRc is set to SQLITE_CORRUPT and NULL is returned.
+** detected then *pRc is set to SQLITE_CORRUPT and NULL is returned.
-** Or, if corruption is detected and pRc is NULL, NULL is returned and the
-** corruption goes unreported.
 **
 ** If a slot of at least nByte bytes is found but cannot be used because 
 ** there are already at least 60 fragmented bytes on the page, return NULL.
@@ -1250,7 +1248,7 @@ static u8 *pageFindSlot(MemPage *pPg, int nByte, int *pRc, int *pbDefrag){
   for(iAddr=hdr+1; (pc = get2byte(&aData[iAddr]))>0; iAddr=pc){
     int size;            /* Size of the free slot */
     if( pc>usableSize-4 || pc<iAddr+4 ){
-      if( pRc ) *pRc = SQLITE_CORRUPT_BKPT;
+      *pRc = SQLITE_CORRUPT_BKPT;
       return 0;
     }
     size = get2byte(&aData[pc+2]);
@@ -1268,7 +1266,7 @@ static u8 *pageFindSlot(MemPage *pPg, int nByte, int *pRc, int *pbDefrag){
         memcpy(&aData[iAddr], &aData[pc], 2);
         aData[hdr+7] += (u8)x;
       }else if( size+pc > usableSize ){
-        if( pRc ) *pRc = SQLITE_CORRUPT_BKPT;
+        *pRc = SQLITE_CORRUPT_BKPT;
         return 0;
       }else{
         /* The slot remains on the free-list. Reduce its size to account
@@ -6076,8 +6074,9 @@ static int pageInsertArray(
   assert( CORRUPT_DB || pPg->hdrOffset==0 );    /* Never called on page 1 */
   for(i=0; i<nCell; i++){
     int sz = szCell[i];
+    int rc;
     u8 *pSlot;
-    if( bFreelist==0 || (pSlot = pageFindSlot(pPg, sz, 0, 0))==0 ){
+    if( bFreelist==0 || (pSlot = pageFindSlot(pPg, sz, &rc, 0))==0 ){
       pData -= sz;
       if( pData<pBegin ) return 1;
       pSlot = pData;
@@ -6870,8 +6869,9 @@ static int balance_nonroot(
         /* This branch is taken if the set of sibling pages somehow contains
         ** duplicate entries. This can happen if the database is corrupt. 
         ** It would be simpler to detect this as part of the loop below, but
-        ** in order to avoid populating the pager cache with two separate
+        ** we do the detection here in order to avoid populating the pager
-        ** objects associated with the same page number.  */
+        ** cache with two separate objects associated with the same
+        ** page number.  */
         assert( CORRUPT_DB );
         rc = SQLITE_CORRUPT_BKPT;
         goto balance_cleanup;
@@ -6956,7 +6956,7 @@ static int balance_nonroot(
       }
 
       /* Cell pCell is destined for new sibling page pNew. Originally, it
-      ** was either part of sibling page iOld (possibly an overflow page), 
+      ** was either part of sibling page iOld (possibly an overflow cell), 
       ** or else the divider cell to the left of sibling page iOld. So,
       ** if sibling page iOld had the same page number as pNew, and if
       ** pCell really was a part of sibling page iOld (not a divider or