Merge fixes from the 3.21 branch.

FossilOrigin-Name: 292921692c8919d29f0a67d03ca953d5c1c4900d8c8567cceab27513732be598

3 files changed, 3 insertions, 2 deletions

diff --git a/src/btree.c b/src/btree.c
index 1496588f8..89222197b 100644
--- a/src/btree.c
+++ b/src/btree.c
@@ -2040,7 +2040,7 @@ static Pgno btreePagecount(BtShared *pBt){
 }
 u32 sqlite3BtreeLastPage(Btree *p){
   assert( sqlite3BtreeHoldsMutex(p) );
-  assert( ((p->pBt->nPage)&0x8000000)==0 );
+  assert( ((p->pBt->nPage)&0x80000000)==0 );
   return btreePagecount(p->pBt);
 }
 
diff --git a/src/shell.c b/src/shell.c
index 06ffb32b8..1537d64a0 100644
--- a/src/shell.c
+++ b/src/shell.c
@@ -3801,7 +3801,7 @@ static char **tableColumnList(ShellState *p, const char *zTab){
     }
   }
   sqlite3_finalize(pStmt);
-  if( !azCol ) return 0;
+  if( azCol==0 ) return 0;
   azCol[0] = 0;
   azCol[nCol+1] = 0;
 
diff --git a/src/shell.c.in b/src/shell.c.in
index db4f2e112..896d475ed 100644
--- a/src/shell.c.in
+++ b/src/shell.c.in
@@ -2441,6 +2441,7 @@ static char **tableColumnList(ShellState *p, const char *zTab){
     }
   }
   sqlite3_finalize(pStmt);
+  if( azCol==0 ) return 0;
   azCol[0] = 0;
   azCol[nCol+1] = 0;