merge(3p/git): Merge git subtree at v2.29.2 r/1890

This also bumps the stable nixpkgs to 20.09 as of 2020-11-21, because
there is some breakage in the git build related to the netrc
credentials helper which someone has taken care of in nixpkgs.

The stable channel is not used for anything other than git, so this
should be fine.

Change-Id: I3575a19dab09e1e9556cf8231d717de9890484fb

1 files changed, 35 insertions, 4 deletions

diff --git a/third_party/git/compat/mingw.h b/third_party/git/compat/mingw.h
index a03e40e6e2a6..af8eddd73edb 100644
--- a/third_party/git/compat/mingw.h
+++ b/third_party/git/compat/mingw.h
@@ -11,7 +11,7 @@ typedef _sigset_t sigset_t;
 #undef _POSIX_THREAD_SAFE_FUNCTIONS
 #endif
 
-extern int mingw_core_config(const char *var, const char *value, void *cb);
+int mingw_core_config(const char *var, const char *value, void *cb);
 #define platform_core_config mingw_core_config
 
 /*
@@ -443,7 +443,7 @@ static inline void convert_slashes(char *path)
 			*path = '/';
 }
 #define PATH_SEP ';'
-extern char *mingw_query_user_email(void);
+char *mingw_query_user_email(void);
 #define query_user_email mingw_query_user_email
 #if !defined(__MINGW64_VERSION_MAJOR) && (!defined(_MSC_VER) || _MSC_VER < 1800)
 #define PRIuMAX "I64u"
@@ -453,6 +453,27 @@ extern char *mingw_query_user_email(void);
 #endif
 
 /**
+ * Verifies that the given path is a valid one on Windows.
+ *
+ * In particular, path segments are disallowed which
+ *
+ * - end in a period or a space (except the special directories `.` and `..`).
+ *
+ * - contain any of the reserved characters, e.g. `:`, `;`, `*`, etc
+ *
+ * - correspond to reserved names (such as `AUX`, `PRN`, etc)
+ *
+ * The `allow_literal_nul` parameter controls whether the path `NUL` should
+ * be considered valid (this makes sense e.g. before opening files, as it is
+ * perfectly legitimate to open `NUL` on Windows, just as it is to open
+ * `/dev/null` on Unix/Linux).
+ *
+ * Returns 1 upon success, otherwise 0.
+ */
+int is_valid_win32_path(const char *path, int allow_literal_nul);
+#define is_valid_path(path) is_valid_win32_path(path, 0)
+
+/**
  * Converts UTF-8 encoded string to UTF-16LE.
  *
  * To support repositories with legacy-encoded file names, invalid UTF-8 bytes
@@ -558,7 +579,7 @@ int xwcstoutf(char *utf, const wchar_t *wcs, size_t utflen);
 
 /*
  * A critical section used in the implementation of the spawn
- * functions (mingw_spawnv[p]e()) and waitpid(). Intialised in
+ * functions (mingw_spawnv[p]e()) and waitpid(). Initialised in
  * the replacement main() macro below.
  */
 extern CRITICAL_SECTION pinfo_cs;
@@ -578,6 +599,16 @@ int wmain(int argc, const wchar_t **w_argv);
 int main(int argc, const char **argv);
 
 /*
+ * For debugging: if a problem occurs, say, in a Git process that is spawned
+ * from another Git process which in turn is spawned from yet another Git
+ * process, it can be quite daunting to figure out what is going on.
+ *
+ * Call this function to open a new MinTTY (this assumes you are in Git for
+ * Windows' SDK) with a GDB that attaches to the current process right away.
+ */
+void open_in_gdb(void);
+
+/*
  * Used by Pthread API implementation for Windows
  */
-extern int err_win_to_posix(DWORD winerr);
+int err_win_to_posix(DWORD winerr);