dir.c: coding style fix

index e65888d..3068ca8 100644
@@ -557,8 +557,7 @@ int add_excludes_from_file_to_list(const char *fname,
 			buf = xrealloc(buf, size+1);
 			buf[size++] = '\n';
 		}
-	}
-	else {
+	} else {
 		size = xsize_t(st.st_size);
 		if (size == 0) {
 			close(fd);

@@ -793,9 +792,11 @@ static void prep_exclude(struct dir_struct *dir, const char *base, int baselen)
 
 	group = &dir->exclude_list_group[EXC_DIRS];
 
-	/* Pop the exclude lists from the EXCL_DIRS exclude_list_group
+	/*
+	 * Pop the exclude lists from the EXCL_DIRS exclude_list_group
 	 * which originate from directories not in the prefix of the
-	 * path being checked. */
+	 * path being checked.
+	 */
 	while ((stk = dir->exclude_stack) != NULL) {
 		if (stk->baselen <= baselen &&
 		    !strncmp(dir->basebuf, base, stk->baselen))

@@ -822,8 +823,7 @@ static void prep_exclude(struct dir_struct *dir, const char *base, int baselen)
 		if (current < 0) {
 			cp = base;
 			current = 0;
-		}
-		else {
+		} else {
 			cp = strchr(base + current + 1, '/');
 			if (!cp)
 				die("oops in prep_exclude");

index 55e5345..02e3710 100644
@@ -15,6 +15,27 @@ struct dir_entry {
 #define EXC_FLAG_MUSTBEDIR 8
 #define EXC_FLAG_NEGATIVE 16
 
+struct exclude {
+	/*
+	 * This allows callers of last_exclude_matching() etc.
+	 * to determine the origin of the matching pattern.
+	 */
+	struct exclude_list *el;
+
+	const char *pattern;
+	int patternlen;
+	int nowildcardlen;
+	const char *base;
+	int baselen;
+	int flags;
+
+	/*
+	 * Counting starts from 1 for line numbers in ignore files,
+	 * and from -1 decrementing for patterns from CLI args.
+	 */
+	int srcpos;
+};
+
 /*
  * Each excludes file will be parsed into a fresh exclude_list which
  * is appended to the relevant exclude_list_group (either EXC_DIRS or

@@ -32,26 +53,7 @@ struct exclude_list {
 	/* origin of list, e.g. path to filename, or descriptive string */
 	const char *src;
 
-	struct exclude {
-		/*
-		 * This allows callers of last_exclude_matching() etc.
-		 * to determine the origin of the matching pattern.
-		 */
-		struct exclude_list *el;
-
-		const char *pattern;
-		int patternlen;
-		int nowildcardlen;
-		const char *base;
-		int baselen;
-		int flags;
-
-		/*
-		 * Counting starts from 1 for line numbers in ignore files,
-		 * and from -1 decrementing for patterns from CLI args.
-		 */
-		int srcpos;
-	} **excludes;
+	struct exclude **excludes;
 };
 
 /*

index 3068ca8..fcb6872 100644
@@ -799,12 +799,12 @@ static void prep_exclude(struct dir_struct *dir, const char *base, int baselen)
 	 */
 	while ((stk = dir->exclude_stack) != NULL) {
 		if (stk->baselen <= baselen &&
-		    !strncmp(dir->basebuf, base, stk->baselen))
+		    !strncmp(dir->basebuf.buf, base, stk->baselen))
 			break;
 		el = &group->el[dir->exclude_stack->exclude_ix];
 		dir->exclude_stack = stk->prev;
 		dir->exclude = NULL;
-		free((char *)el->src); /* see strdup() below */
+		free((char *)el->src); /* see strbuf_detach() below */
 		clear_exclude_list(el);
 		free(stk);
 		group->nr--;

@@ -814,8 +814,17 @@ static void prep_exclude(struct dir_struct *dir, const char *base, int baselen)
 	if (dir->exclude)
 		return;
 
+	/*
+	 * Lazy initialization. All call sites currently just
+	 * memset(dir, 0, sizeof(*dir)) before use. Changing all of
+	 * them seems lots of work for little benefit.
+	 */
+	if (!dir->basebuf.buf)
+		strbuf_init(&dir->basebuf, PATH_MAX);
+
 	/* Read from the parent directories and push them down. */
 	current = stk ? stk->baselen : -1;
+	strbuf_setlen(&dir->basebuf, current < 0 ? 0 : current);
 	while (current < baselen) {
 		struct exclude_stack *stk = xcalloc(1, sizeof(*stk));
 		const char *cp;

@@ -833,48 +842,47 @@ static void prep_exclude(struct dir_struct *dir, const char *base, int baselen)
 		stk->baselen = cp - base;
 		stk->exclude_ix = group->nr;
 		el = add_exclude_list(dir, EXC_DIRS, NULL);
-		memcpy(dir->basebuf + current, base + current,
-		       stk->baselen - current);
+		strbuf_add(&dir->basebuf, base + current, stk->baselen - current);
+		assert(stk->baselen == dir->basebuf.len);
 
 		/* Abort if the directory is excluded */
 		if (stk->baselen) {
 			int dt = DT_DIR;
-			dir->basebuf[stk->baselen - 1] = 0;
+			dir->basebuf.buf[stk->baselen - 1] = 0;
 			dir->exclude = last_exclude_matching_from_lists(dir,
-				dir->basebuf, stk->baselen - 1,
-				dir->basebuf + current, &dt);
-			dir->basebuf[stk->baselen - 1] = '/';
+				dir->basebuf.buf, stk->baselen - 1,
+				dir->basebuf.buf + current, &dt);
+			dir->basebuf.buf[stk->baselen - 1] = '/';
 			if (dir->exclude &&
 			    dir->exclude->flags & EXC_FLAG_NEGATIVE)
 				dir->exclude = NULL;
 			if (dir->exclude) {
-				dir->basebuf[stk->baselen] = 0;
 				dir->exclude_stack = stk;
 				return;
 			}
 		}
 
-		/* Try to read per-directory file unless path is too long */
-		if (dir->exclude_per_dir &&
-		    stk->baselen + strlen(dir->exclude_per_dir) < PATH_MAX) {
-			strcpy(dir->basebuf + stk->baselen,
-					dir->exclude_per_dir);
+		/* Try to read per-directory file */
+		if (dir->exclude_per_dir) {
 			/*
 			 * dir->basebuf gets reused by the traversal, but we
 			 * need fname to remain unchanged to ensure the src
 			 * member of each struct exclude correctly
 			 * back-references its source file.  Other invocations
 			 * of add_exclude_list provide stable strings, so we
-			 * strdup() and free() here in the caller.
+			 * strbuf_detach() and free() here in the caller.
 			 */
-			el->src = strdup(dir->basebuf);
-			add_excludes_from_file_to_list(dir->basebuf,
-					dir->basebuf, stk->baselen, el, 1);
+			struct strbuf sb = STRBUF_INIT;
+			strbuf_addbuf(&sb, &dir->basebuf);
+			strbuf_addstr(&sb, dir->exclude_per_dir);
+			el->src = strbuf_detach(&sb, NULL);
+			add_excludes_from_file_to_list(el->src, el->src,
+						       stk->baselen, el, 1);
 		}
 		dir->exclude_stack = stk;
 		current = stk->baselen;
 	}
-	dir->basebuf[baselen] = '\0';
+	strbuf_setlen(&dir->basebuf, baselen);
 }
 
 /*

@@ -1671,4 +1679,5 @@ void clear_directory(struct dir_struct *dir)
 		free(stk);
 		stk = prev;
 	}
+	strbuf_release(&dir->basebuf);
 }

index 02e3710..6c45e9d 100644
@@ -119,7 +119,7 @@ struct dir_struct {
 	 */
 	struct exclude_stack *exclude_stack;
 	struct exclude *exclude;
-	char basebuf[PATH_MAX];
+	struct strbuf basebuf;
 };
 
 /*