dir: store EXC_FLAG_* values in unsigned integers

The values defined by the macro EXC_FLAG_* (1, 4, 8, 16) are stored
in fields of the structs "pattern" and "exclude", some functions
arguments and a local variable.  None of these uses its most
significant bit in any special way and there is no good reason to
use a signed integer for them.

And while we're at it, document "flags" of "exclude" to explicitly
state the values it's supposed to take on.

Signed-off-by: Saurav Sachidanand <sauravsachidanand@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

attr.c

@@ -124,7 +124,7 @@ struct pattern {
 	const char *pattern;
 	int patternlen;
 	int nowildcardlen;
-	int flags;		/* EXC_FLAG_* */
+	unsigned flags;		/* EXC_FLAG_* */
 };
 
 /*

dir.c

@@ -441,7 +441,7 @@ int no_wildcard(const char *string)
 
 void parse_exclude_pattern(const char **pattern,
 			   int *patternlen,
-			   int *flags,
+			   unsigned *flags,
 			   int *nowildcardlen)
 {
 	const char *p = *pattern;
@@ -482,7 +482,7 @@ void add_exclude(const char *string, const char *base,
 {
 	struct exclude *x;
 	int patternlen;
-	int flags;
+	unsigned flags;
 	int nowildcardlen;
 
 	parse_exclude_pattern(&string, &patternlen, &flags, &nowildcardlen);
@@ -663,7 +663,7 @@ void add_excludes_from_file(struct dir_struct *dir, const char *fname)
 
 int match_basename(const char *basename, int basenamelen,
 		   const char *pattern, int prefix, int patternlen,
-		   int flags)
+		   unsigned flags)
 {
 	if (prefix == patternlen) {
 		if (patternlen == basenamelen &&
@@ -688,7 +688,7 @@ int match_basename(const char *basename, int basenamelen,
 int match_pathname(const char *pathname, int pathlen,
 		   const char *base, int baselen,
 		   const char *pattern, int prefix, int patternlen,
-		   int flags)
+		   unsigned flags)
 {
 	const char *name;
 	int namelen;

dir.h

@@ -27,7 +27,7 @@ struct exclude {
 	int nowildcardlen;
 	const char *base;
 	int baselen;
-	int flags;
+	unsigned flags;		/* EXC_FLAG_* */
 
 	/*
 	 * Counting starts from 1 for line numbers in ignore files,
@@ -152,10 +152,10 @@ struct dir_entry *dir_add_ignored(struct dir_struct *dir, const char *pathname,
  * attr.c:path_matches()
  */
 extern int match_basename(const char *, int,
-			  const char *, int, int, int);
+			  const char *, int, int, unsigned);
 extern int match_pathname(const char *, int,
 			  const char *, int,
-			  const char *, int, int, int);
+			  const char *, int, int, unsigned);
 
 extern struct exclude *last_exclude_matching(struct dir_struct *dir,
 					     const char *name, int *dtype);
@@ -167,7 +167,7 @@ extern struct exclude_list *add_exclude_list(struct dir_struct *dir,
 extern int add_excludes_from_file_to_list(const char *fname, const char *base, int baselen,
 					  struct exclude_list *el, int check_index);
 extern void add_excludes_from_file(struct dir_struct *, const char *fname);
-extern void parse_exclude_pattern(const char **string, int *patternlen, int *flags, int *nowildcardlen);
+extern void parse_exclude_pattern(const char **string, int *patternlen, unsigned *flags, int *nowildcardlen);
 extern void add_exclude(const char *string, const char *base,
 			int baselen, struct exclude_list *el, int srcpos);
 extern void clear_exclude_list(struct exclude_list *el);