Test coverage improvements in the FTS3 porter stemmer.

FossilOrigin-Name: 6d112bfd53998b8f6693d3f2edbcd5ab4cdf5fb1

ext/fts3/fts3Int.h

@@ -53,6 +53,15 @@
 */
 #define FTS3_VARINT_MAX 10
 
+/*
+** Macros indicating that conditional expressions are always true or
+** false.
+*/
+#ifndef SQLITE_AMALGAMATION
+# define ALWAYS(x) (x)
+# define NEVER(X)  (x)
+#endif
+
 typedef struct Fts3Table Fts3Table;
 typedef struct Fts3Cursor Fts3Cursor;
 typedef struct Fts3Expr Fts3Expr;

ext/fts3/fts3_porter.c

@@ -234,7 +234,7 @@ static int hasVowel(const char *z){
 ** the first two characters of z[].
 */
 static int doubleConsonant(const char *z){
-  return isConsonant(z) && z[0]==z[1] && isConsonant(z+1);
+  return isConsonant(z) && z[0]==z[1];
 }
 
 /*
@@ -247,10 +247,10 @@ static int doubleConsonant(const char *z){
 */
 static int star_oh(const char *z){
   return
-    z[0]!=0 && isConsonant(z) &&
+    isConsonant(z) &&
     z[0]!='w' && z[0]!='x' && z[0]!='y' &&
-    z[1]!=0 && isVowel(z+1) &&
-    z[2]!=0 && isConsonant(z+2);
+    isVowel(z+1) &&
+    isConsonant(z+2);
 }
 
 /*

ext/fts3/fts3_snippet.c

@@ -545,7 +545,7 @@ static int wordBoundary(
   if( iBreak>=nDoc-10 ){
     return nDoc;
   }
-  for(i=0; i<nMatch && aMatch[i].iCol<iCol; i++){}
+  for(i=0; ALWAYS(i<nMatch) && aMatch[i].iCol<iCol; i++){}
   while( i<nMatch && aMatch[i].iStart+aMatch[i].nByte<iBreak ){ i++; }
   if( i<nMatch ){
     if( aMatch[i].iStart<iBreak+10 ){