Fix compiler warnings. Better comments on some variables associated with

LIKE/GLOB processing in the query planner.

FossilOrigin-Name: cfa2db0ff7a94e7f66c35f672ee41cadd45a6dd7

src/btree.c

@@ -6454,7 +6454,7 @@ int sqlite3BtreeInsert(
 ){
   int rc;
   int loc = seekResult;          /* -1: before desired location  +1: after */
-  int szNew;
+  int szNew = 0;
   int idx;
   MemPage *pPage;
   Btree *p = pCur->pBtree;

src/os_unix.c

@@ -2542,7 +2542,8 @@ static int afpLock(sqlite3_file *id, int locktype){
   ** operating system calls for the specified lock.
   */
   if( locktype==SHARED_LOCK ){
-    int lk, lrc1, lrc2, lrc1Errno;
+    int lk, lrc1, lrc2;
+    int lrc1Errno = 0;
     
     /* Now get the read-lock SHARED_LOCK */
     /* note that the quality of the randomness doesn't matter that much */

src/where.c

@@ -1098,13 +1098,13 @@ static void exprAnalyze(
   Expr *pExpr;                     /* The expression to be analyzed */
   Bitmask prereqLeft;              /* Prerequesites of the pExpr->pLeft */
   Bitmask prereqAll;               /* Prerequesites of pExpr */
-  Bitmask extraRight = 0;
-  int isComplete;
-  int noCase;
+  Bitmask extraRight = 0;          /* */
+  Expr *pStr1 = 0;                 /* RHS of LIKE/GLOB operator */
+  int isComplete = 0;              /* RHS of LIKE/GLOB ends with wildcard */
+  int noCase = 0;                  /* LIKE/GLOB distinguishes case */
   int op;                          /* Top-level operator.  pExpr->op */
   Parse *pParse = pWC->pParse;     /* Parsing context */
   sqlite3 *db = pParse->db;        /* Database connection */
-  Expr *pStr1;
 
   if( db->mallocFailed ){
     return;
@@ -1239,10 +1239,12 @@ static void exprAnalyze(
   if( pWC->op==TK_AND 
    && isLikeOrGlob(pParse, pExpr, &pStr1, &isComplete, &noCase)
   ){
-    Expr *pLeft;
-    Expr *pStr2;
-    Expr *pNewExpr1, *pNewExpr2;
-    int idxNew1, idxNew2;
+    Expr *pLeft;       /* LHS of LIKE/GLOB operator */
+    Expr *pStr2;       /* Copy of pStr1 - RHS of LIKE/GLOB operator */
+    Expr *pNewExpr1;
+    Expr *pNewExpr2;
+    int idxNew1;
+    int idxNew2;
 
     pLeft = pExpr->x.pList->a[1].pExpr;
     pStr2 = sqlite3ExprDup(db, pStr1, 0);