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, 39 insertions, 64 deletions

diff --git a/third_party/git/wrapper.c b/third_party/git/wrapper.c
index 1e45ab7b9274..bcda41e3744c 100644
--- a/third_party/git/wrapper.c
+++ b/third_party/git/wrapper.c
@@ -4,12 +4,6 @@
 #include "cache.h"
 #include "config.h"
 
-static void do_nothing(size_t size)
-{
-}
-
-static void (*try_to_free_routine)(size_t size) = do_nothing;
-
 static int memory_limit_check(size_t size, int gentle)
 {
 	static size_t limit = 0;
@@ -30,24 +24,11 @@ static int memory_limit_check(size_t size, int gentle)
 	return 0;
 }
 
-try_to_free_t set_try_to_free_routine(try_to_free_t routine)
-{
-	try_to_free_t old = try_to_free_routine;
-	if (!routine)
-		routine = do_nothing;
-	try_to_free_routine = routine;
-	return old;
-}
-
 char *xstrdup(const char *str)
 {
 	char *ret = strdup(str);
-	if (!ret) {
-		try_to_free_routine(strlen(str) + 1);
-		ret = strdup(str);
-		if (!ret)
-			die("Out of memory, strdup failed");
-	}
+	if (!ret)
+		die("Out of memory, strdup failed");
 	return ret;
 }
 
@@ -61,19 +42,13 @@ static void *do_xmalloc(size_t size, int gentle)
 	if (!ret && !size)
 		ret = malloc(1);
 	if (!ret) {
-		try_to_free_routine(size);
-		ret = malloc(size);
-		if (!ret && !size)
-			ret = malloc(1);
-		if (!ret) {
-			if (!gentle)
-				die("Out of memory, malloc failed (tried to allocate %lu bytes)",
-				    (unsigned long)size);
-			else {
-				error("Out of memory, malloc failed (tried to allocate %lu bytes)",
-				      (unsigned long)size);
-				return NULL;
-			}
+		if (!gentle)
+			die("Out of memory, malloc failed (tried to allocate %lu bytes)",
+			    (unsigned long)size);
+		else {
+			error("Out of memory, malloc failed (tried to allocate %lu bytes)",
+			      (unsigned long)size);
+			return NULL;
 		}
 	}
 #ifdef XMALLOC_POISON
@@ -130,22 +105,27 @@ char *xstrndup(const char *str, size_t len)
 	return xmemdupz(str, p ? p - str : len);
 }
 
+int xstrncmpz(const char *s, const char *t, size_t len)
+{
+	int res = strncmp(s, t, len);
+	if (res)
+		return res;
+	return s[len] == '\0' ? 0 : 1;
+}
+
 void *xrealloc(void *ptr, size_t size)
 {
 	void *ret;
 
+	if (!size) {
+		free(ptr);
+		return xmalloc(0);
+	}
+
 	memory_limit_check(size, 0);
 	ret = realloc(ptr, size);
-	if (!ret && !size)
-		ret = realloc(ptr, 1);
-	if (!ret) {
-		try_to_free_routine(size);
-		ret = realloc(ptr, size);
-		if (!ret && !size)
-			ret = realloc(ptr, 1);
-		if (!ret)
-			die("Out of memory, realloc failed");
-	}
+	if (!ret)
+		die("Out of memory, realloc failed");
 	return ret;
 }
 
@@ -160,14 +140,8 @@ void *xcalloc(size_t nmemb, size_t size)
 	ret = calloc(nmemb, size);
 	if (!ret && (!nmemb || !size))
 		ret = calloc(1, 1);
-	if (!ret) {
-		try_to_free_routine(nmemb * size);
-		ret = calloc(nmemb, size);
-		if (!ret && (!nmemb || !size))
-			ret = calloc(1, 1);
-		if (!ret)
-			die("Out of memory, calloc failed");
-	}
+	if (!ret)
+		die("Out of memory, calloc failed");
 	return ret;
 }
 
@@ -255,7 +229,7 @@ ssize_t xread(int fd, void *buf, size_t len)
 {
 	ssize_t nr;
 	if (len > MAX_IO_SIZE)
-	    len = MAX_IO_SIZE;
+		len = MAX_IO_SIZE;
 	while (1) {
 		nr = read(fd, buf, len);
 		if (nr < 0) {
@@ -277,7 +251,7 @@ ssize_t xwrite(int fd, const void *buf, size_t len)
 {
 	ssize_t nr;
 	if (len > MAX_IO_SIZE)
-	    len = MAX_IO_SIZE;
+		len = MAX_IO_SIZE;
 	while (1) {
 		nr = write(fd, buf, len);
 		if (nr < 0) {
@@ -478,7 +452,9 @@ int git_mkstemps_mode(char *pattern, int suffix_len, int mode)
 		"abcdefghijklmnopqrstuvwxyz"
 		"ABCDEFGHIJKLMNOPQRSTUVWXYZ"
 		"0123456789";
-	static const int num_letters = 62;
+	static const int num_letters = ARRAY_SIZE(letters) - 1;
+	static const char x_pattern[] = "XXXXXX";
+	static const int num_x = ARRAY_SIZE(x_pattern) - 1;
 	uint64_t value;
 	struct timeval tv;
 	char *filename_template;
@@ -487,12 +463,12 @@ int git_mkstemps_mode(char *pattern, int suffix_len, int mode)
 
 	len = strlen(pattern);
 
-	if (len < 6 + suffix_len) {
+	if (len < num_x + suffix_len) {
 		errno = EINVAL;
 		return -1;
 	}
 
-	if (strncmp(&pattern[len - 6 - suffix_len], "XXXXXX", 6)) {
+	if (strncmp(&pattern[len - num_x - suffix_len], x_pattern, num_x)) {
 		errno = EINVAL;
 		return -1;
 	}
@@ -503,16 +479,15 @@ int git_mkstemps_mode(char *pattern, int suffix_len, int mode)
 	 */
 	gettimeofday(&tv, NULL);
 	value = ((uint64_t)tv.tv_usec << 16) ^ tv.tv_sec ^ getpid();
-	filename_template = &pattern[len - 6 - suffix_len];
+	filename_template = &pattern[len - num_x - suffix_len];
 	for (count = 0; count < TMP_MAX; ++count) {
 		uint64_t v = value;
+		int i;
 		/* Fill in the random bits. */
-		filename_template[0] = letters[v % num_letters]; v /= num_letters;
-		filename_template[1] = letters[v % num_letters]; v /= num_letters;
-		filename_template[2] = letters[v % num_letters]; v /= num_letters;
-		filename_template[3] = letters[v % num_letters]; v /= num_letters;
-		filename_template[4] = letters[v % num_letters]; v /= num_letters;
-		filename_template[5] = letters[v % num_letters]; v /= num_letters;
+		for (i = 0; i < num_x; i++) {
+			filename_template[i] = letters[v % num_letters];
+			v /= num_letters;
+		}
 
 		fd = open(pattern, O_CREAT | O_EXCL | O_RDWR, mode);
 		if (fd >= 0)