Fix harmless scan-build warnings.

FossilOrigin-Name: beab3c98639be531744e60440223bb9ee76bc15234aff05e5efb273c8241dfd8

src/btree.c

@@ -5341,6 +5341,7 @@ static int moveToChild(BtCursor *pCur, u32 newPgno){
   pCur->ix = 0;
   pCur->iPage++;
   rc = getAndInitPage(pCur->pBt, newPgno, &pCur->pPage, pCur->curPagerFlags);
+  assert( pCur->pPage!=0 || rc!=SQLITE_OK );
   if( rc==SQLITE_OK
    && (pCur->pPage->nCell<1 || pCur->pPage->intKey!=pCur->curIntKey)
   ){
@@ -5569,7 +5570,7 @@ int sqlite3BtreeFirst(BtCursor *pCur, int *pRes){
     *pRes = 0;
     rc = moveToLeftmost(pCur);
   }else if( rc==SQLITE_EMPTY ){
-    assert( pCur->pgnoRoot==0 || pCur->pPage->nCell==0 );
+    assert( pCur->pgnoRoot==0 || (pCur->pPage!=0 && pCur->pPage->nCell==0) );
     *pRes = 1;
     rc = SQLITE_OK;
   }

src/util.c

@@ -933,6 +933,11 @@ int sqlite3Atoi(const char *z){
 ** n is positive.  Or round to -n signficant digits after the
 ** decimal point if n is negative.  No rounding is performed if
 ** n is zero.
+**
+** The significant digits of the decimal representation are
+** stored in p->z[] which is a often (but not always) a pointer
+** into the middle of p->zBuf[].  There are p->n significant digits.
+** The p->z[] array is *not* zero-terminated.
 */
 void sqlite3FpDecode(FpDecode *p, double r, int iRound, int mxRound){
   int i;
@@ -1025,14 +1030,16 @@ void sqlite3FpDecode(FpDecode *p, double r, int iRound, int mxRound){
 
   /* Extract significant digits. */
   i = sizeof(p->zBuf)-1;
+  assert( v>0 );
   while( v ){  p->zBuf[i--] = (v%10) + '0'; v /= 10; }
-  assert( i>=0 );
+  assert( i>=0 && i<sizeof(p->zBuf)-1 );
   p->n = sizeof(p->zBuf) - 1 - i;
+  assert( p->n>0 );
   assert( p->n<sizeof(p->zBuf) );
   p->iDP = p->n + exp;
   if( iRound<0 ){
     iRound = p->iDP - iRound;
-    if( iRound==0 && p->z[i+1]>='5' ){
+    if( iRound==0 && p->zBuf[i+1]>='5' ){
       iRound = 1;
       p->zBuf[i--] = '0';
       p->n++;
@@ -1061,6 +1068,7 @@ void sqlite3FpDecode(FpDecode *p, double r, int iRound, int mxRound){
     }
   }
   p->z = &p->zBuf[i+1];
+  assert( i+p->n < sizeof(p->zBuf) );
   while( ALWAYS(p->n>0) && p->z[p->n-1]=='0' ){ p->n--; }
 }