Reverse the order of two conditionals in a test in order to achieve coverage

of them both.  Also: clarifications to comments in btree.c. (CVS 6912)

FossilOrigin-Name: a159e9d24708dfe6c5a98d220e39f3b1b2a3d281

manifest

@@ -1,5 +1,5 @@
-C Modify\svarious\sroutines\sinside\sbtree.c\sto\stake\sa\spointer\sto\sthe\sreturn-code\nas\sa\sparameter\sand\sto\sno-op\sif\sthe\sreturn-code\sstorage\slocation\salready\ncontains\sa\snon-zero\scode.\s(CVS\s6911)
-D 2009-07-20T17:11:50
+C Reverse\sthe\sorder\sof\stwo\sconditionals\sin\sa\stest\sin\sorder\sto\sachieve\scoverage\nof\sthem\sboth.\s\sAlso:\sclarifications\sto\scomments\sin\sbtree.c.\s(CVS\s6912)
+D 2009-07-20T19:30:01
 F Makefile.arm-wince-mingw32ce-gcc fcd5e9cd67fe88836360bb4f9ef4cb7f8e2fb5a0
 F Makefile.in df9359da7a726ccb67a45db905c5447d5c00c6ef
 F Makefile.linux-gcc d53183f4aa6a9192d249731c90dbdffbd2c68654
@@ -106,7 +106,7 @@ F src/auth.c 802a9439dfa0b8c208b10055cba400e82ef18025
 F src/backup.c 6f1c2d9862c8a3feb7739dfcca02c1f5352e37f3
 F src/bitvec.c cfbf6af5b0ababb4f06ed3e75c616dadaf47fcbd
 F src/btmutex.c 0f43a75bb5b8147b386e8e1c3e71ba734e3863b7
-F src/btree.c a597d1d9608c88d6ce06f89c396fb560d244f2bc
+F src/btree.c 123dd6ab71226ee9c41d6658fd11b2f7bed73f44
 F src/btree.h e53a10fd31d16c60a86f03c9467a6f470aa3683b
 F src/btreeInt.h 1c86297e69380f6577e7ae67452597dd8d5c2705
 F src/build.c 867028ee9f63f7bc8eb8d4a720bb98cf9b9a12b4
@@ -741,7 +741,7 @@ F tool/speedtest2.tcl ee2149167303ba8e95af97873c575c3e0fab58ff
 F tool/speedtest8.c 2902c46588c40b55661e471d7a86e4dd71a18224
 F tool/speedtest8inst1.c 293327bc76823f473684d589a8160bde1f52c14e
 F tool/vdbe-compress.tcl 672f81d693a03f80f5ae60bfefacd8a349e76746
-P 609022caff12c010575e704be550da6f52226d33
-R f0dac37b25de3361940901b7ede7713d
+P 7dcf2a78727ce448d9d26bd6e2e23b553456ec54
+R ee81aff6c227cadf19a47a764a1a15d2
 U drh
-Z 0886d43bf9f8d479825e913af0119cfa
+Z f9f7c95bd23663f1ba6a8b648cb1cde3

manifest.uuid

@@ -1 +1 @@
-7dcf2a78727ce448d9d26bd6e2e23b553456ec54
+a159e9d24708dfe6c5a98d220e39f3b1b2a3d281

src/btree.c

@@ -9,7 +9,7 @@
 **    May you share freely, never taking more than you give.
 **
 *************************************************************************
-** $Id: btree.c,v 1.692 2009/07/20 17:11:50 drh Exp $
+** $Id: btree.c,v 1.693 2009/07/20 19:30:01 drh Exp $
 **
 ** This file implements a external (disk-based) database using BTrees.
 ** See the header comment on "btreeInt.h" for additional information.
@@ -5590,9 +5590,9 @@ static int copyNodeContent(MemPage *pFrom, MemPage *pTo){
 ** be rolled back.
 **
 ** The third argument to this function, aOvflSpace, is a pointer to a
-** buffer page-size bytes in size. If, in inserting cells into the parent
-** page (pParent), the parent page becomes overfull, this buffer is
-** used to store the parents overflow cells. Because this function inserts
+** buffer big enough to hold one page. If while inserting cells into the parent
+** page (pParent) the parent page becomes overfull, this buffer is
+** used to store the parent's overflow cells. Because this function inserts
 ** a maximum of four divider cells into the parent page, and the maximum
 ** size of a cell stored within an internal node is always less than 1/4
 ** of the page-size, the aOvflSpace[] buffer is guaranteed to be large
@@ -5646,7 +5646,8 @@ static int balance_nonroot(
   /* At this point pParent may have at most one overflow cell. And if
   ** this overflow cell is present, it must be the cell with 
   ** index iParentIdx. This scenario comes about when this function
-  ** is called (indirectly) from sqlite3BtreeDelete(). */
+  ** is called (indirectly) from sqlite3BtreeDelete().
+  */
   assert( pParent->nOverflow==0 || pParent->nOverflow==1 );
   assert( pParent->nOverflow==0 || pParent->aOvfl[0].idx==iParentIdx );
 
@@ -5662,8 +5663,9 @@ static int balance_nonroot(
   **
   ** This loop also drops the divider cells from the parent page. This
   ** way, the remainder of the function does not have to deal with any
-  ** overflow cells in the parent page, as if one existed it has already
-  ** been removed.  */
+  ** overflow cells in the parent page, since if any existed they will
+  ** have already been removed.
+  */
   i = pParent->nOverflow + pParent->nCell;
   if( i<2 ){
     nxDiv = 0;
@@ -5694,7 +5696,7 @@ static int balance_nonroot(
     nMaxCells += 1+apOld[i]->nCell+apOld[i]->nOverflow;
     if( (i--)==0 ) break;
 
-    if( pParent->nOverflow && i+nxDiv==pParent->aOvfl[0].idx ){
+    if( i+nxDiv==pParent->aOvfl[0].idx && pParent->nOverflow ){
       apDiv[i] = pParent->aOvfl[0].pCell;
       pgno = get4byte(apDiv[i]);
       szNew[i] = cellSizePtr(pParent, apDiv[i]);