dir.c: don't exclude whole dir prematurely if neg pattern may match

If there is a pattern "!foo/bar", this patch makes it not exclude "foo"
right away. This gives us a chance to examine "foo" and re-include
"foo/bar".

In order for it to detect that the directory under examination should
not be excluded right away, in other words it is a parent directory of a
negative pattern, the "directory path" of the negative pattern must be
literal. Patterns like "!f?o/bar" can't stop "foo" from being excluded.

Basename matching (i.e. "no slashes in the pattern") or must-be-dir
matching (i.e. "trailing slash in the pattern") does not work well with
this. For example, if we descend in "foo" and are examining "foo/abc",
current code for "foo/" pattern will check if path "foo/abc", not "foo",
is a directory. The same problem with basename matching. These may need
big code reorg to make it work.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/Documentation/gitignore.txt b/Documentation/gitignore.txt
index 4fd04423e9342e05d34b4a72a4e1af802b8c10c8..9cce703c5a0aab53cc86e00992447880e8f400cd 100644 (file)
--- a/Documentation/gitignore.txt
+++ b/Documentation/gitignore.txt
@@ -82,12 +82,12 @@ PATTERN FORMAT
 
  - An optional prefix "`!`" which negates the pattern; any
    matching file excluded by a previous pattern will become
 
  - An optional prefix "`!`" which negates the pattern; any
    matching file excluded by a previous pattern will become

-   included again. It is not possible to re-include a file if a parent
-   directory of that file is excluded. Git doesn't list excluded
-   directories for performance reasons, so any patterns on contained
-   files have no effect, no matter where they are defined.
+   included again.

    Put a backslash ("`\`") in front of the first "`!`" for patterns
    that begin with a literal "`!`", for example, "`\!important!.txt`".
    Put a backslash ("`\`") in front of the first "`!`" for patterns
    that begin with a literal "`!`", for example, "`\!important!.txt`".

+   It is possible to re-include a file if a parent directory of that
+   file is excluded if certain conditions are met. See section NOTES
+   for detail.

 
  - If the pattern ends with a slash, it is removed for the
    purpose of the following description, but it would only find
 
  - If the pattern ends with a slash, it is removed for the
    purpose of the following description, but it would only find


@@ -141,6 +141,21 @@ not tracked by Git remain untracked.
 To stop tracking a file that is currently tracked, use
 'git rm --cached'.
 
 To stop tracking a file that is currently tracked, use
 'git rm --cached'.
 

+To re-include files or directories when their parent directory is
+excluded, the following conditions must be met:
+
+ - The rules to exclude a directory and re-include a subset back must
+   be in the same .gitignore file.
+
+ - The directory part in the re-include rules must be literal (i.e. no
+   wildcards)
+
+ - The rules to exclude the parent directory must not end with a
+   trailing slash.
+
+ - The rules to exclude the parent directory must have at least one
+   slash.
+

 EXAMPLES
 --------
 
 EXAMPLES
 --------
 

diff --git a/dir.c b/dir.c
index 4893181a0c5774b158b67ff47a3adf6d342beb64..894027c0cd7e6a3983c55c1564e67dc2957f392e 100644 (file)
--- a/dir.c
+++ b/dir.c
@@ -733,6 +733,25 @@ int match_pathname(const char *pathname, int pathlen,
                 */
                if (!patternlen && !namelen)
                        return 1;
                 */
                if (!patternlen && !namelen)
                        return 1;

+               /*
+                * This can happen when we ignore some exclude rules
+                * on directories in other to see if negative rules
+                * may match. E.g.
+                *
+                * /abc
+                * !/abc/def/ghi
+                *
+                * The pattern of interest is "/abc". On the first
+                * try, we should match path "abc" with this pattern
+                * in the "if" statement right above, but the caller
+                * ignores it.
+                *
+                * On the second try with paths within "abc",
+                * e.g. "abc/xyz", we come here and try to match it
+                * with "/abc".
+                */
+               if (!patternlen && namelen && *name == '/')
+                       return 1;

        }
 
        return fnmatch_icase_mem(pattern, patternlen,
        }
 
        return fnmatch_icase_mem(pattern, patternlen,


@@ -740,6 +759,48 @@ int match_pathname(const char *pathname, int pathlen,
                                 WM_PATHNAME) == 0;
 }
 
                                 WM_PATHNAME) == 0;
 }
 

+/*
+ * Return non-zero if pathname is a directory and an ancestor of the
+ * literal path in a (negative) pattern. This is used to keep
+ * descending in "foo" and "foo/bar" when the pattern is
+ * "!foo/bar/.gitignore". "foo/notbar" will not be descended however.
+ */
+static int match_neg_path(const char *pathname, int pathlen, int *dtype,
+                         const char *base, int baselen,
+                         const char *pattern, int prefix, int patternlen,
+                         int flags)
+{
+       assert((flags & EXC_FLAG_NEGATIVE) && !(flags & EXC_FLAG_NODIR));
+
+       if (*dtype == DT_UNKNOWN)
+               *dtype = get_dtype(NULL, pathname, pathlen);
+       if (*dtype != DT_DIR)
+               return 0;
+
+       if (*pattern == '/') {
+               pattern++;
+               patternlen--;
+               prefix--;
+       }
+
+       if (baselen) {
+               if (((pathlen < baselen && base[pathlen] == '/') ||
+                    pathlen == baselen) &&
+                   !strncmp_icase(pathname, base, pathlen))
+                       return 1;
+               pathname += baselen + 1;
+               pathlen  -= baselen + 1;
+       }
+
+
+       if (prefix &&
+           ((pathlen < prefix && pattern[pathlen] == '/') &&
+            !strncmp_icase(pathname, pattern, pathlen)))
+               return 1;
+
+       return 0;
+}
+

 /*
  * Scan the given exclude list in reverse to see whether pathname
  * should be ignored.  The first match (i.e. the last on the list), if
 /*
  * Scan the given exclude list in reverse to see whether pathname
  * should be ignored.  The first match (i.e. the last on the list), if


@@ -753,7 +814,7 @@ static struct exclude *last_exclude_matching_from_list(const char *pathname,
                                                       struct exclude_list *el)
 {
        struct exclude *exc = NULL; /* undecided */
                                                       struct exclude_list *el)
 {
        struct exclude *exc = NULL; /* undecided */

-       int i;
+       int i, matched_negative_path = 0;

 
        if (!el->nr)
                return NULL;    /* undefined */
 
        if (!el->nr)
                return NULL;    /* undefined */


@@ -788,7 +849,18 @@ static struct exclude *last_exclude_matching_from_list(const char *pathname,
                        exc = x;
                        break;
                }
                        exc = x;
                        break;
                }

+
+               if ((x->flags & EXC_FLAG_NEGATIVE) && !matched_negative_path &&
+                   match_neg_path(pathname, pathlen, dtype, x->base,
+                                  x->baselen ? x->baselen - 1 : 0,
+                                  exclude, prefix, x->patternlen, x->flags))
+                       matched_negative_path = 1;

        }
        }

+       if (exc &&
+           !(exc->flags & EXC_FLAG_NEGATIVE) &&
+           !(exc->flags & EXC_FLAG_NODIR) &&
+           matched_negative_path)
+               exc = NULL;

        return exc;
 }
 
        return exc;
 }
 

diff --git a/t/t3001-ls-files-others-exclude.sh b/t/t3001-ls-files-others-exclude.sh
index b2798feef7316e74584058f594e97af01cb5065e..2a13af17585d6af89943d65cf1dc6edf407f01fa 100755 (executable)
--- a/t/t3001-ls-files-others-exclude.sh
+++ b/t/t3001-ls-files-others-exclude.sh
@@ -305,4 +305,29 @@ test_expect_success 'ls-files with "**" patterns and no slashes' '
        test_cmp expect actual
 '
 
        test_cmp expect actual
 '
 

+test_expect_success 'negative patterns' '
+       git init reinclude &&
+       (
+               cd reinclude &&
+               cat >.gitignore <<-\EOF &&
+               /fooo
+               /foo
+               !foo/bar/bar
+               EOF
+               mkdir fooo &&
+               cat >fooo/.gitignore <<-\EOF &&
+               !/*
+               EOF
+               mkdir -p foo/bar &&
+               touch abc foo/def foo/bar/ghi foo/bar/bar &&
+               git ls-files -o --exclude-standard >../actual &&
+               cat >../expected <<-\EOF &&
+               .gitignore
+               abc
+               foo/bar/bar
+               EOF
+               test_cmp ../expected ../actual
+       )
+'
+

 test_done
 test_done