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-rw-r--r--tree-walk.c681
1 files changed, 643 insertions, 38 deletions
diff --git a/tree-walk.c b/tree-walk.c
index a9bbf4e235..ce27842439 100644
--- a/tree-walk.c
+++ b/tree-walk.c
@@ -1,7 +1,9 @@
#include "cache.h"
#include "tree-walk.h"
#include "unpack-trees.h"
+#include "dir.h"
#include "tree.h"
+#include "pathspec.h"
static const char *get_mode(const char *str, unsigned int *modep)
{
@@ -35,8 +37,8 @@ static void decode_tree_entry(struct tree_desc *desc, const char *buf, unsigned
/* Initialize the descriptor entry */
desc->entry.path = path;
- desc->entry.mode = mode;
- desc->entry.sha1 = (const unsigned char *)(path + len);
+ desc->entry.mode = canon_mode(mode);
+ desc->entry.oid = (const struct object_id *)(path + len);
}
void init_tree_desc(struct tree_desc *desc, const void *buffer, unsigned long size)
@@ -74,7 +76,7 @@ static void entry_extract(struct tree_desc *t, struct name_entry *a)
void update_tree_entry(struct tree_desc *desc)
{
const void *buf = desc->buffer;
- const unsigned char *end = desc->entry.sha1 + 20;
+ const unsigned char *end = desc->entry.oid->hash + 20;
unsigned long size = desc->size;
unsigned long len = end - (const unsigned char *)buf;
@@ -108,14 +110,14 @@ void setup_traverse_info(struct traverse_info *info, const char *base)
pathlen--;
info->pathlen = pathlen ? pathlen + 1 : 0;
info->name.path = base;
- info->name.sha1 = (void *)(base + pathlen + 1);
+ info->name.oid = (void *)(base + pathlen + 1);
if (pathlen)
info->prev = &dummy;
}
char *make_traverse_path(char *path, const struct traverse_info *info, const struct name_entry *n)
{
- int len = tree_entry_len(n->path, n->sha1);
+ int len = tree_entry_len(n);
int pathlen = info->pathlen;
path[pathlen + len] = 0;
@@ -125,7 +127,7 @@ char *make_traverse_path(char *path, const struct traverse_info *info, const str
break;
path[--pathlen] = '/';
n = &info->name;
- len = tree_entry_len(n->path, n->sha1);
+ len = tree_entry_len(n);
info = info->prev;
pathlen -= len;
}
@@ -142,16 +144,6 @@ struct tree_desc_x {
struct tree_desc_skip *skip;
};
-static int name_compare(const char *a, int a_len,
- const char *b, int b_len)
-{
- int len = (a_len < b_len) ? a_len : b_len;
- int cmp = memcmp(a, b, len);
- if (cmp)
- return cmp;
- return (a_len - b_len);
-}
-
static int check_entry_match(const char *a, int a_len, const char *b, int b_len)
{
/*
@@ -252,7 +244,7 @@ static void extended_entry_extract(struct tree_desc_x *t,
* The caller wants "first" from this tree, or nothing.
*/
path = a->path;
- len = tree_entry_len(a->path, a->sha1);
+ len = tree_entry_len(a);
switch (check_entry_match(first, first_len, path, len)) {
case -1:
entry_clear(a);
@@ -270,7 +262,7 @@ static void extended_entry_extract(struct tree_desc_x *t,
while (probe.size) {
entry_extract(&probe, a);
path = a->path;
- len = tree_entry_len(a->path, a->sha1);
+ len = tree_entry_len(a);
switch (check_entry_match(first, first_len, path, len)) {
case -1:
entry_clear(a);
@@ -308,22 +300,47 @@ static void free_extended_entry(struct tree_desc_x *t)
}
}
+static inline int prune_traversal(struct name_entry *e,
+ struct traverse_info *info,
+ struct strbuf *base,
+ int still_interesting)
+{
+ if (!info->pathspec || still_interesting == 2)
+ return 2;
+ if (still_interesting < 0)
+ return still_interesting;
+ return tree_entry_interesting(e, base, 0, info->pathspec);
+}
+
int traverse_trees(int n, struct tree_desc *t, struct traverse_info *info)
{
- int ret = 0;
int error = 0;
struct name_entry *entry = xmalloc(n*sizeof(*entry));
int i;
struct tree_desc_x *tx = xcalloc(n, sizeof(*tx));
+ struct strbuf base = STRBUF_INIT;
+ int interesting = 1;
+ char *traverse_path;
for (i = 0; i < n; i++)
tx[i].d = t[i];
+ if (info->prev) {
+ strbuf_grow(&base, info->pathlen);
+ make_traverse_path(base.buf, info->prev, &info->name);
+ base.buf[info->pathlen-1] = '/';
+ strbuf_setlen(&base, info->pathlen);
+ traverse_path = xstrndup(base.buf, info->pathlen);
+ } else {
+ traverse_path = xstrndup(info->name.path, info->pathlen);
+ }
+ info->traverse_path = traverse_path;
for (;;) {
+ int trees_used;
unsigned long mask, dirmask;
const char *first = NULL;
int first_len = 0;
- struct name_entry *e;
+ struct name_entry *e = NULL;
int len;
for (i = 0; i < n; i++) {
@@ -341,7 +358,7 @@ int traverse_trees(int n, struct tree_desc *t, struct traverse_info *info)
e = entry + i;
if (!e->path)
continue;
- len = tree_entry_len(e->path, e->sha1);
+ len = tree_entry_len(e);
if (!first) {
first = e->path;
first_len = len;
@@ -360,7 +377,7 @@ int traverse_trees(int n, struct tree_desc *t, struct traverse_info *info)
/* Cull the ones that are not the earliest */
if (!e->path)
continue;
- len = tree_entry_len(e->path, e->sha1);
+ len = tree_entry_len(e);
if (name_compare(e->path, len, first, first_len))
entry_clear(e);
}
@@ -375,17 +392,22 @@ int traverse_trees(int n, struct tree_desc *t, struct traverse_info *info)
mask |= 1ul << i;
if (S_ISDIR(entry[i].mode))
dirmask |= 1ul << i;
+ e = &entry[i];
}
if (!mask)
break;
- ret = info->fn(n, mask, dirmask, entry, info);
- if (ret < 0) {
- error = ret;
- if (!info->show_all_errors)
- break;
+ interesting = prune_traversal(e, info, &base, interesting);
+ if (interesting < 0)
+ break;
+ if (interesting) {
+ trees_used = info->fn(n, mask, dirmask, entry, info);
+ if (trees_used < 0) {
+ error = trees_used;
+ if (!info->show_all_errors)
+ break;
+ }
+ mask &= trees_used;
}
- mask &= ret;
- ret = 0;
for (i = 0; i < n; i++)
if (mask & (1ul << i))
update_extended_entry(tx + i, entry + i);
@@ -394,20 +416,29 @@ int traverse_trees(int n, struct tree_desc *t, struct traverse_info *info)
for (i = 0; i < n; i++)
free_extended_entry(tx + i);
free(tx);
+ free(traverse_path);
+ info->traverse_path = NULL;
+ strbuf_release(&base);
return error;
}
+struct dir_state {
+ void *tree;
+ unsigned long size;
+ unsigned char sha1[20];
+};
+
static int find_tree_entry(struct tree_desc *t, const char *name, unsigned char *result, unsigned *mode)
{
int namelen = strlen(name);
while (t->size) {
const char *entry;
- const unsigned char *sha1;
+ const struct object_id *oid;
int entrylen, cmp;
- sha1 = tree_entry_extract(t, &entry, mode);
+ oid = tree_entry_extract(t, &entry, mode);
+ entrylen = tree_entry_len(&t->entry);
update_tree_entry(t);
- entrylen = tree_entry_len(entry, sha1);
if (entrylen > namelen)
continue;
cmp = memcmp(name, entry, entrylen);
@@ -416,7 +447,7 @@ static int find_tree_entry(struct tree_desc *t, const char *name, unsigned char
if (cmp < 0)
break;
if (entrylen == namelen) {
- hashcpy(result, sha1);
+ hashcpy(result, oid->hash);
return 0;
}
if (name[entrylen] != '/')
@@ -424,10 +455,10 @@ static int find_tree_entry(struct tree_desc *t, const char *name, unsigned char
if (!S_ISDIR(*mode))
break;
if (++entrylen == namelen) {
- hashcpy(result, sha1);
+ hashcpy(result, oid->hash);
return 0;
}
- return get_tree_entry(sha1, name + entrylen, result, mode);
+ return get_tree_entry(oid->hash, name + entrylen, result, mode);
}
return -1;
}
@@ -437,7 +468,6 @@ int get_tree_entry(const unsigned char *tree_sha1, const char *name, unsigned ch
int retval;
void *tree;
unsigned long size;
- struct tree_desc t;
unsigned char root[20];
tree = read_object_with_reference(tree_sha1, tree_type, &size, root);
@@ -450,8 +480,583 @@ int get_tree_entry(const unsigned char *tree_sha1, const char *name, unsigned ch
return 0;
}
- init_tree_desc(&t, tree, size);
- retval = find_tree_entry(&t, name, sha1, mode);
+ if (!size) {
+ retval = -1;
+ } else {
+ struct tree_desc t;
+ init_tree_desc(&t, tree, size);
+ retval = find_tree_entry(&t, name, sha1, mode);
+ }
free(tree);
return retval;
}
+
+/*
+ * This is Linux's built-in max for the number of symlinks to follow.
+ * That limit, of course, does not affect git, but it's a reasonable
+ * choice.
+ */
+#define GET_TREE_ENTRY_FOLLOW_SYMLINKS_MAX_LINKS 40
+
+/**
+ * Find a tree entry by following symlinks in tree_sha (which is
+ * assumed to be the root of the repository). In the event that a
+ * symlink points outside the repository (e.g. a link to /foo or a
+ * root-level link to ../foo), the portion of the link which is
+ * outside the repository will be returned in result_path, and *mode
+ * will be set to 0. It is assumed that result_path is uninitialized.
+ * If there are no symlinks, or the end result of the symlink chain
+ * points to an object inside the repository, result will be filled in
+ * with the sha1 of the found object, and *mode will hold the mode of
+ * the object.
+ *
+ * See the code for enum follow_symlink_result for a description of
+ * the return values.
+ */
+enum follow_symlinks_result get_tree_entry_follow_symlinks(unsigned char *tree_sha1, const char *name, unsigned char *result, struct strbuf *result_path, unsigned *mode)
+{
+ int retval = MISSING_OBJECT;
+ struct dir_state *parents = NULL;
+ size_t parents_alloc = 0;
+ ssize_t parents_nr = 0;
+ unsigned char current_tree_sha1[20];
+ struct strbuf namebuf = STRBUF_INIT;
+ struct tree_desc t;
+ int follows_remaining = GET_TREE_ENTRY_FOLLOW_SYMLINKS_MAX_LINKS;
+ int i;
+
+ init_tree_desc(&t, NULL, 0UL);
+ strbuf_init(result_path, 0);
+ strbuf_addstr(&namebuf, name);
+ hashcpy(current_tree_sha1, tree_sha1);
+
+ while (1) {
+ int find_result;
+ char *first_slash;
+ char *remainder = NULL;
+
+ if (!t.buffer) {
+ void *tree;
+ unsigned char root[20];
+ unsigned long size;
+ tree = read_object_with_reference(current_tree_sha1,
+ tree_type, &size,
+ root);
+ if (!tree)
+ goto done;
+
+ ALLOC_GROW(parents, parents_nr + 1, parents_alloc);
+ parents[parents_nr].tree = tree;
+ parents[parents_nr].size = size;
+ hashcpy(parents[parents_nr].sha1, root);
+ parents_nr++;
+
+ if (namebuf.buf[0] == '\0') {
+ hashcpy(result, root);
+ retval = FOUND;
+ goto done;
+ }
+
+ if (!size)
+ goto done;
+
+ /* descend */
+ init_tree_desc(&t, tree, size);
+ }
+
+ /* Handle symlinks to e.g. a//b by removing leading slashes */
+ while (namebuf.buf[0] == '/') {
+ strbuf_remove(&namebuf, 0, 1);
+ }
+
+ /* Split namebuf into a first component and a remainder */
+ if ((first_slash = strchr(namebuf.buf, '/'))) {
+ *first_slash = 0;
+ remainder = first_slash + 1;
+ }
+
+ if (!strcmp(namebuf.buf, "..")) {
+ struct dir_state *parent;
+ /*
+ * We could end up with .. in the namebuf if it
+ * appears in a symlink.
+ */
+
+ if (parents_nr == 1) {
+ if (remainder)
+ *first_slash = '/';
+ strbuf_add(result_path, namebuf.buf,
+ namebuf.len);
+ *mode = 0;
+ retval = FOUND;
+ goto done;
+ }
+ parent = &parents[parents_nr - 1];
+ free(parent->tree);
+ parents_nr--;
+ parent = &parents[parents_nr - 1];
+ init_tree_desc(&t, parent->tree, parent->size);
+ strbuf_remove(&namebuf, 0, remainder ? 3 : 2);
+ continue;
+ }
+
+ /* We could end up here via a symlink to dir/.. */
+ if (namebuf.buf[0] == '\0') {
+ hashcpy(result, parents[parents_nr - 1].sha1);
+ retval = FOUND;
+ goto done;
+ }
+
+ /* Look up the first (or only) path component in the tree. */
+ find_result = find_tree_entry(&t, namebuf.buf,
+ current_tree_sha1, mode);
+ if (find_result) {
+ goto done;
+ }
+
+ if (S_ISDIR(*mode)) {
+ if (!remainder) {
+ hashcpy(result, current_tree_sha1);
+ retval = FOUND;
+ goto done;
+ }
+ /* Descend the tree */
+ t.buffer = NULL;
+ strbuf_remove(&namebuf, 0,
+ 1 + first_slash - namebuf.buf);
+ } else if (S_ISREG(*mode)) {
+ if (!remainder) {
+ hashcpy(result, current_tree_sha1);
+ retval = FOUND;
+ } else {
+ retval = NOT_DIR;
+ }
+ goto done;
+ } else if (S_ISLNK(*mode)) {
+ /* Follow a symlink */
+ unsigned long link_len;
+ size_t len;
+ char *contents, *contents_start;
+ struct dir_state *parent;
+ enum object_type type;
+
+ if (follows_remaining-- == 0) {
+ /* Too many symlinks followed */
+ retval = SYMLINK_LOOP;
+ goto done;
+ }
+
+ /*
+ * At this point, we have followed at a least
+ * one symlink, so on error we need to report this.
+ */
+ retval = DANGLING_SYMLINK;
+
+ contents = read_sha1_file(current_tree_sha1, &type,
+ &link_len);
+
+ if (!contents)
+ goto done;
+
+ if (contents[0] == '/') {
+ strbuf_addstr(result_path, contents);
+ free(contents);
+ *mode = 0;
+ retval = FOUND;
+ goto done;
+ }
+
+ if (remainder)
+ len = first_slash - namebuf.buf;
+ else
+ len = namebuf.len;
+
+ contents_start = contents;
+
+ parent = &parents[parents_nr - 1];
+ init_tree_desc(&t, parent->tree, parent->size);
+ strbuf_splice(&namebuf, 0, len,
+ contents_start, link_len);
+ if (remainder)
+ namebuf.buf[link_len] = '/';
+ free(contents);
+ }
+ }
+done:
+ for (i = 0; i < parents_nr; i++)
+ free(parents[i].tree);
+ free(parents);
+
+ strbuf_release(&namebuf);
+ return retval;
+}
+
+static int match_entry(const struct pathspec_item *item,
+ const struct name_entry *entry, int pathlen,
+ const char *match, int matchlen,
+ enum interesting *never_interesting)
+{
+ int m = -1; /* signals that we haven't called strncmp() */
+
+ if (item->magic & PATHSPEC_ICASE)
+ /*
+ * "Never interesting" trick requires exact
+ * matching. We could do something clever with inexact
+ * matching, but it's trickier (and not to forget that
+ * strcasecmp is locale-dependent, at least in
+ * glibc). Just disable it for now. It can't be worse
+ * than the wildcard's codepath of '[Tt][Hi][Is][Ss]'
+ * pattern.
+ */
+ *never_interesting = entry_not_interesting;
+ else if (*never_interesting != entry_not_interesting) {
+ /*
+ * We have not seen any match that sorts later
+ * than the current path.
+ */
+
+ /*
+ * Does match sort strictly earlier than path
+ * with their common parts?
+ */
+ m = strncmp(match, entry->path,
+ (matchlen < pathlen) ? matchlen : pathlen);
+ if (m < 0)
+ return 0;
+
+ /*
+ * If we come here even once, that means there is at
+ * least one pathspec that would sort equal to or
+ * later than the path we are currently looking at.
+ * In other words, if we have never reached this point
+ * after iterating all pathspecs, it means all
+ * pathspecs are either outside of base, or inside the
+ * base but sorts strictly earlier than the current
+ * one. In either case, they will never match the
+ * subsequent entries. In such a case, we initialized
+ * the variable to -1 and that is what will be
+ * returned, allowing the caller to terminate early.
+ */
+ *never_interesting = entry_not_interesting;
+ }
+
+ if (pathlen > matchlen)
+ return 0;
+
+ if (matchlen > pathlen) {
+ if (match[pathlen] != '/')
+ return 0;
+ if (!S_ISDIR(entry->mode) && !S_ISGITLINK(entry->mode))
+ return 0;
+ }
+
+ if (m == -1)
+ /*
+ * we cheated and did not do strncmp(), so we do
+ * that here.
+ */
+ m = ps_strncmp(item, match, entry->path, pathlen);
+
+ /*
+ * If common part matched earlier then it is a hit,
+ * because we rejected the case where path is not a
+ * leading directory and is shorter than match.
+ */
+ if (!m)
+ /*
+ * match_entry does not check if the prefix part is
+ * matched case-sensitively. If the entry is a
+ * directory and part of prefix, it'll be rematched
+ * eventually by basecmp with special treatment for
+ * the prefix.
+ */
+ return 1;
+
+ return 0;
+}
+
+/* :(icase)-aware string compare */
+static int basecmp(const struct pathspec_item *item,
+ const char *base, const char *match, int len)
+{
+ if (item->magic & PATHSPEC_ICASE) {
+ int ret, n = len > item->prefix ? item->prefix : len;
+ ret = strncmp(base, match, n);
+ if (ret)
+ return ret;
+ base += n;
+ match += n;
+ len -= n;
+ }
+ return ps_strncmp(item, base, match, len);
+}
+
+static int match_dir_prefix(const struct pathspec_item *item,
+ const char *base,
+ const char *match, int matchlen)
+{
+ if (basecmp(item, base, match, matchlen))
+ return 0;
+
+ /*
+ * If the base is a subdirectory of a path which
+ * was specified, all of them are interesting.
+ */
+ if (!matchlen ||
+ base[matchlen] == '/' ||
+ match[matchlen - 1] == '/')
+ return 1;
+
+ /* Just a random prefix match */
+ return 0;
+}
+
+/*
+ * Perform matching on the leading non-wildcard part of
+ * pathspec. item->nowildcard_len must be greater than zero. Return
+ * non-zero if base is matched.
+ */
+static int match_wildcard_base(const struct pathspec_item *item,
+ const char *base, int baselen,
+ int *matched)
+{
+ const char *match = item->match;
+ /* the wildcard part is not considered in this function */
+ int matchlen = item->nowildcard_len;
+
+ if (baselen) {
+ int dirlen;
+ /*
+ * Return early if base is longer than the
+ * non-wildcard part but it does not match.
+ */
+ if (baselen >= matchlen) {
+ *matched = matchlen;
+ return !basecmp(item, base, match, matchlen);
+ }
+
+ dirlen = matchlen;
+ while (dirlen && match[dirlen - 1] != '/')
+ dirlen--;
+
+ /*
+ * Return early if base is shorter than the
+ * non-wildcard part but it does not match. Note that
+ * base ends with '/' so we are sure it really matches
+ * directory
+ */
+ if (basecmp(item, base, match, baselen))
+ return 0;
+ *matched = baselen;
+ } else
+ *matched = 0;
+ /*
+ * we could have checked entry against the non-wildcard part
+ * that is not in base and does similar never_interesting
+ * optimization as in match_entry. For now just be happy with
+ * base comparison.
+ */
+ return entry_interesting;
+}
+
+/*
+ * Is a tree entry interesting given the pathspec we have?
+ *
+ * Pre-condition: either baselen == base_offset (i.e. empty path)
+ * or base[baselen-1] == '/' (i.e. with trailing slash).
+ */
+static enum interesting do_match(const struct name_entry *entry,
+ struct strbuf *base, int base_offset,
+ const struct pathspec *ps,
+ int exclude)
+{
+ int i;
+ int pathlen, baselen = base->len - base_offset;
+ enum interesting never_interesting = ps->has_wildcard ?
+ entry_not_interesting : all_entries_not_interesting;
+
+ GUARD_PATHSPEC(ps,
+ PATHSPEC_FROMTOP |
+ PATHSPEC_MAXDEPTH |
+ PATHSPEC_LITERAL |
+ PATHSPEC_GLOB |
+ PATHSPEC_ICASE |
+ PATHSPEC_EXCLUDE);
+
+ if (!ps->nr) {
+ if (!ps->recursive ||
+ !(ps->magic & PATHSPEC_MAXDEPTH) ||
+ ps->max_depth == -1)
+ return all_entries_interesting;
+ return within_depth(base->buf + base_offset, baselen,
+ !!S_ISDIR(entry->mode),
+ ps->max_depth) ?
+ entry_interesting : entry_not_interesting;
+ }
+
+ pathlen = tree_entry_len(entry);
+
+ for (i = ps->nr - 1; i >= 0; i--) {
+ const struct pathspec_item *item = ps->items+i;
+ const char *match = item->match;
+ const char *base_str = base->buf + base_offset;
+ int matchlen = item->len, matched = 0;
+
+ if ((!exclude && item->magic & PATHSPEC_EXCLUDE) ||
+ ( exclude && !(item->magic & PATHSPEC_EXCLUDE)))
+ continue;
+
+ if (baselen >= matchlen) {
+ /* If it doesn't match, move along... */
+ if (!match_dir_prefix(item, base_str, match, matchlen))
+ goto match_wildcards;
+
+ if (!ps->recursive ||
+ !(ps->magic & PATHSPEC_MAXDEPTH) ||
+ ps->max_depth == -1)
+ return all_entries_interesting;
+
+ return within_depth(base_str + matchlen + 1,
+ baselen - matchlen - 1,
+ !!S_ISDIR(entry->mode),
+ ps->max_depth) ?
+ entry_interesting : entry_not_interesting;
+ }
+
+ /* Either there must be no base, or the base must match. */
+ if (baselen == 0 || !basecmp(item, base_str, match, baselen)) {
+ if (match_entry(item, entry, pathlen,
+ match + baselen, matchlen - baselen,
+ &never_interesting))
+ return entry_interesting;
+
+ if (item->nowildcard_len < item->len) {
+ if (!git_fnmatch(item, match + baselen, entry->path,
+ item->nowildcard_len - baselen))
+ return entry_interesting;
+
+ /*
+ * Match all directories. We'll try to
+ * match files later on.
+ */
+ if (ps->recursive && S_ISDIR(entry->mode))
+ return entry_interesting;
+ }
+
+ continue;
+ }
+
+match_wildcards:
+ if (item->nowildcard_len == item->len)
+ continue;
+
+ if (item->nowildcard_len &&
+ !match_wildcard_base(item, base_str, baselen, &matched))
+ continue;
+
+ /*
+ * Concatenate base and entry->path into one and do
+ * fnmatch() on it.
+ *
+ * While we could avoid concatenation in certain cases
+ * [1], which saves a memcpy and potentially a
+ * realloc, it turns out not worth it. Measurement on
+ * linux-2.6 does not show any clear improvements,
+ * partly because of the nowildcard_len optimization
+ * in git_fnmatch(). Avoid micro-optimizations here.
+ *
+ * [1] if match_wildcard_base() says the base
+ * directory is already matched, we only need to match
+ * the rest, which is shorter so _in theory_ faster.
+ */
+
+ strbuf_add(base, entry->path, pathlen);
+
+ if (!git_fnmatch(item, match, base->buf + base_offset,
+ item->nowildcard_len)) {
+ strbuf_setlen(base, base_offset + baselen);
+ return entry_interesting;
+ }
+ strbuf_setlen(base, base_offset + baselen);
+
+ /*
+ * Match all directories. We'll try to match files
+ * later on.
+ * max_depth is ignored but we may consider support it
+ * in future, see
+ * http://thread.gmane.org/gmane.comp.version-control.git/163757/focus=163840
+ */
+ if (ps->recursive && S_ISDIR(entry->mode))
+ return entry_interesting;
+ }
+ return never_interesting; /* No matches */
+}
+
+/*
+ * Is a tree entry interesting given the pathspec we have?
+ *
+ * Pre-condition: either baselen == base_offset (i.e. empty path)
+ * or base[baselen-1] == '/' (i.e. with trailing slash).
+ */
+enum interesting tree_entry_interesting(const struct name_entry *entry,
+ struct strbuf *base, int base_offset,
+ const struct pathspec *ps)
+{
+ enum interesting positive, negative;
+ positive = do_match(entry, base, base_offset, ps, 0);
+
+ /*
+ * case | entry | positive | negative | result
+ * -----+-------+----------+----------+-------
+ * 1 | file | -1 | -1..2 | -1
+ * 2 | file | 0 | -1..2 | 0
+ * 3 | file | 1 | -1 | 1
+ * 4 | file | 1 | 0 | 1
+ * 5 | file | 1 | 1 | 0
+ * 6 | file | 1 | 2 | 0
+ * 7 | file | 2 | -1 | 2
+ * 8 | file | 2 | 0 | 2
+ * 9 | file | 2 | 1 | 0
+ * 10 | file | 2 | 2 | -1
+ * -----+-------+----------+----------+-------
+ * 11 | dir | -1 | -1..2 | -1
+ * 12 | dir | 0 | -1..2 | 0
+ * 13 | dir | 1 | -1 | 1
+ * 14 | dir | 1 | 0 | 1
+ * 15 | dir | 1 | 1 | 1 (*)
+ * 16 | dir | 1 | 2 | 0
+ * 17 | dir | 2 | -1 | 2
+ * 18 | dir | 2 | 0 | 2
+ * 19 | dir | 2 | 1 | 1 (*)
+ * 20 | dir | 2 | 2 | -1
+ *
+ * (*) An exclude pattern interested in a directory does not
+ * necessarily mean it will exclude all of the directory. In
+ * wildcard case, it can't decide until looking at individual
+ * files inside. So don't write such directories off yet.
+ */
+
+ if (!(ps->magic & PATHSPEC_EXCLUDE) ||
+ positive <= entry_not_interesting) /* #1, #2, #11, #12 */
+ return positive;
+
+ negative = do_match(entry, base, base_offset, ps, 1);
+
+ /* #3, #4, #7, #8, #13, #14, #17, #18 */
+ if (negative <= entry_not_interesting)
+ return positive;
+
+ /* #15, #19 */
+ if (S_ISDIR(entry->mode) &&
+ positive >= entry_interesting &&
+ negative == entry_interesting)
+ return entry_interesting;
+
+ if ((positive == entry_interesting &&
+ negative >= entry_interesting) || /* #5, #6, #16 */
+ (positive == all_entries_interesting &&
+ negative == entry_interesting)) /* #9 */
+ return entry_not_interesting;
+
+ return all_entries_not_interesting; /* #10, #20 */
+}