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

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

third_party/git/compat/regex/regcomp.c

@@ -3462,7 +3462,7 @@ build_equiv_class (bitset_t sbcset, const unsigned char *name)
 	/* This isn't a valid character.  */
 	return REG_ECOLLATE;
 
-      /* Build single byte matcing table for this equivalence class.  */
+      /* Build single byte matching table for this equivalence class.  */
       char_buf[1] = (unsigned char) '\0';
       len = weights[idx1 & 0xffffff];
       for (ch = 0; ch < SBC_MAX; ++ch)

third_party/git/compat/regex/regex.c

@@ -60,6 +60,7 @@
    #undefs RE_DUP_MAX and sets it to the right value.  */
 #include <limits.h>
 #include <stdint.h>
+#include <stdlib.h>
 
 #ifdef GAWK
 #undef alloca

third_party/git/compat/regex/regex.h

@@ -41,6 +41,11 @@
 extern "C" {
 #endif
 
+#define regcomp git_regcomp
+#define regexec git_regexec
+#define regerror git_regerror
+#define regfree git_regfree
+
 /* The following two types have to be signed and unsigned integer type
    wide enough to hold a value of a pointer.  For most ANSI compilers
    ptrdiff_t and size_t should be likely OK.  Still size of these two
@@ -322,7 +327,7 @@ typedef enum
   /* POSIX regcomp return error codes.  (In the order listed in the
      standard.)  */
   REG_BADPAT,		/* Invalid pattern.  */
-  REG_ECOLLATE,		/* Inalid collating element.  */
+  REG_ECOLLATE,		/* Invalid collating element.  */
   REG_ECTYPE,		/* Invalid character class name.  */
   REG_EESCAPE,		/* Trailing backslash.  */
   REG_ESUBREG,		/* Invalid back reference.  */

third_party/git/compat/regex/regex_internal.c

@@ -1616,7 +1616,7 @@ free_state (re_dfastate_t *state)
   re_free (state);
 }
 
-/* Create the new state which is independ of contexts.
+/* Create the new state which is independent of contexts.
    Return the new state if succeeded, otherwise return NULL.  */
 
 static re_dfastate_t *

third_party/git/compat/regex/regex_internal.h

@@ -23,7 +23,6 @@
 #include <assert.h>
 #include <ctype.h>
 #include <stdio.h>
-#include <stdlib.h>
 #include <string.h>
 
 #if defined HAVE_LANGINFO_H || defined HAVE_LANGINFO_CODESET || defined _LIBC

third_party/git/compat/regex/regexec.c

@@ -2420,7 +2420,7 @@ find_recover_state (reg_errcode_t *err, re_match_context_t *mctx)
 /* From the node set CUR_NODES, pick up the nodes whose types are
    OP_OPEN_SUBEXP and which have corresponding back references in the regular
    expression. And register them to use them later for evaluating the
-   correspoding back references.  */
+   corresponding back references.  */
 
 static reg_errcode_t
 internal_function
@@ -3347,7 +3347,7 @@ build_trtable (const re_dfa_t *dfa, re_dfastate_t *state)
   dests_node = dests_alloc->dests_node;
   dests_ch = dests_alloc->dests_ch;
 
-  /* Initialize transiton table.  */
+  /* Initialize transition table.  */
   state->word_trtable = state->trtable = NULL;
 
   /* At first, group all nodes belonging to `state' into several