Merge branch 'jk/submodule-name-verify-fix' into jk/submodule-name-verify-fsck

* jk/submodule-name-verify-fix:
  verify_path: disallow symlinks in .gitmodules
  update-index: stat updated files earlier
  verify_path: drop clever fallthrough
  skip_prefix: add icase-insensitive variant
  is_{hfs,ntfs}_dotgitmodules: add tests
  path: match NTFS short names for more .git files
  is_hfs_dotgit: match other .git files
  is_ntfs_dotgit: use a size_t for traversing string
  submodule-config: verify submodule names as paths

Note that this includes two bits of evil-merge:

 - there's a new call to verify_path() that doesn't actually
   have a mode available. It should be OK to pass "0" here,
   since we're just manipulating the untracked cache, not an
   actual index entry.

 - the lstat() in builtin/update-index.c:update_one() needs
   to be updated to handle the fsmonitor case (without this
   it still behaves correctly, but does an unnecessary
   lstat).

1 files changed, 85 insertions, 1 deletions

diff --git a/path.c b/path.c
index da8b655730..4c4a751539 100644
--- a/path.c
+++ b/path.c
@@ -1305,7 +1305,7 @@ static int only_spaces_and_periods(const char *path, size_t len, size_t skip)
 
 int is_ntfs_dotgit(const char *name)
 {
-	int len;
+	size_t len;
 
 	for (len = 0; ; len++)
 		if (!name[len] || name[len] == '\\' || is_dir_sep(name[len])) {
@@ -1322,6 +1322,90 @@ int is_ntfs_dotgit(const char *name)
 		}
 }
 
+static int is_ntfs_dot_generic(const char *name,
+			       const char *dotgit_name,
+			       size_t len,
+			       const char *dotgit_ntfs_shortname_prefix)
+{
+	int saw_tilde;
+	size_t i;
+
+	if ((name[0] == '.' && !strncasecmp(name + 1, dotgit_name, len))) {
+		i = len + 1;
+only_spaces_and_periods:
+		for (;;) {
+			char c = name[i++];
+			if (!c)
+				return 1;
+			if (c != ' ' && c != '.')
+				return 0;
+		}
+	}
+
+	/*
+	 * Is it a regular NTFS short name, i.e. shortened to 6 characters,
+	 * followed by ~1, ... ~4?
+	 */
+	if (!strncasecmp(name, dotgit_name, 6) && name[6] == '~' &&
+	    name[7] >= '1' && name[7] <= '4') {
+		i = 8;
+		goto only_spaces_and_periods;
+	}
+
+	/*
+	 * Is it a fall-back NTFS short name (for details, see
+	 * https://en.wikipedia.org/wiki/8.3_filename?
+	 */
+	for (i = 0, saw_tilde = 0; i < 8; i++)
+		if (name[i] == '\0')
+			return 0;
+		else if (saw_tilde) {
+			if (name[i] < '0' || name[i] > '9')
+				return 0;
+		} else if (name[i] == '~') {
+			if (name[++i] < '1' || name[i] > '9')
+				return 0;
+			saw_tilde = 1;
+		} else if (i >= 6)
+			return 0;
+		else if (name[i] < 0) {
+			/*
+			 * We know our needles contain only ASCII, so we clamp
+			 * here to make the results of tolower() sane.
+			 */
+			return 0;
+		} else if (tolower(name[i]) != dotgit_ntfs_shortname_prefix[i])
+			return 0;
+
+	goto only_spaces_and_periods;
+}
+
+/*
+ * Inline helper to make sure compiler resolves strlen() on literals at
+ * compile time.
+ */
+static inline int is_ntfs_dot_str(const char *name, const char *dotgit_name,
+				  const char *dotgit_ntfs_shortname_prefix)
+{
+	return is_ntfs_dot_generic(name, dotgit_name, strlen(dotgit_name),
+				   dotgit_ntfs_shortname_prefix);
+}
+
+int is_ntfs_dotgitmodules(const char *name)
+{
+	return is_ntfs_dot_str(name, "gitmodules", "gi7eba");
+}
+
+int is_ntfs_dotgitignore(const char *name)
+{
+	return is_ntfs_dot_str(name, "gitignore", "gi250a");
+}
+
+int is_ntfs_dotgitattributes(const char *name)
+{
+	return is_ntfs_dot_str(name, "gitattributes", "gi7d29");
+}
+
 int looks_like_command_line_option(const char *str)
 {
 	return str && str[0] == '-';