thodg/libgit2

diff --git a/src/date.c b/src/date.c
index 2297ee6..52cc308 100644
--- a/src/date.c
+++ b/src/date.c
@@ -13,6 +13,7 @@
 #include "util.h"
 #include "cache.h"
 #include "posix.h"
+#include "date.h"
 
 #include <ctype.h>
 #include <time.h>
@@ -857,7 +858,7 @@ static git_time_t approxidate_str(const char *date,
 	return update_tm(&tm, &now, 0);
 }
 
-int git__date_parse(git_time_t *out, const char *date)
+int git_date_parse(git_time_t *out, const char *date)
 {
 	time_t time_sec;
 	git_time_t timestamp;
@@ -875,31 +876,24 @@ int git__date_parse(git_time_t *out, const char *date)
    return error_ret;
 }
 
-int git__date_rfc2822_fmt(char *out, size_t len, const git_time *date)
+int git_date_rfc2822_fmt(git_str *out, git_time_t time, int offset)
 {
-	int written;
-	struct tm gmt;
 	time_t t;
+	struct tm gmt;
 
 	GIT_ASSERT_ARG(out);
-	GIT_ASSERT_ARG(date);
 
-	t = (time_t) (date->time + date->offset * 60);
+	t = (time_t) (time + offset * 60);
 
-	if (p_gmtime_r (&t, &gmt) == NULL)
+	if (p_gmtime_r(&t, &gmt) == NULL)
 		return -1;
 
-	written = p_snprintf(out, len, "%.3s, %u %.3s %.4u %02u:%02u:%02u %+03d%02d",
+	return git_str_printf(out, "%.3s, %u %.3s %.4u %02u:%02u:%02u %+03d%02d",
 		weekday_names[gmt.tm_wday],
 		gmt.tm_mday,
 		month_names[gmt.tm_mon],
 		gmt.tm_year + 1900,
 		gmt.tm_hour, gmt.tm_min, gmt.tm_sec,
-		date->offset / 60, date->offset % 60);
-
-	if (written < 0 || (written > (int) len - 1))
-		return -1;
-
-	return 0;
+		offset / 60, offset % 60);
 }
 
diff --git a/src/date.h b/src/date.h
new file mode 100644
index 0000000..7ebd3c3
--- /dev/null
+++ b/src/date.h
@@ -0,0 +1,33 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_date_h__
+#define INCLUDE_date_h__
+
+#include "util.h"
+#include "str.h"
+
+/*
+ * Parse a string into a value as a git_time_t.
+ *
+ * Sample valid input:
+ * - "yesterday"
+ * - "July 17, 2003"
+ * - "2003-7-17 08:23"
+ */
+extern int git_date_parse(git_time_t *out, const char *date);
+
+/*
+ * Format a git_time as a RFC2822 string
+ *
+ * @param out buffer to store formatted date
+ * @param time the time to be formatted
+ * @param offset the timezone offset
+ * @return 0 if successful; -1 on error
+ */
+extern int git_date_rfc2822_fmt(git_str *out, git_time_t time, int offset);
+
+#endif
diff --git a/src/email.c b/src/email.c
index 3459c05..e19a292 100644
--- a/src/email.c
+++ b/src/email.c
@@ -12,6 +12,7 @@
 #include "diff_generate.h"
 #include "diff_stats.h"
 #include "patch.h"
+#include "date.h"
 
 #include "git2/email.h"
 #include "git2/patch.h"
@@ -72,6 +73,19 @@ static int append_prefix(
 	return git_str_oom(out) ? -1 : 0;
 }
 
+static int append_date(
+	git_str *out,
+	const git_time *date)
+{
+	int error;
+
+	if ((error = git_str_printf(out, "Date: ")) == 0 &&
+	    (error = git_date_rfc2822_fmt(out, date->time, date->offset)) == 0)
+	    error = git_str_putc(out, '\n');
+
+	return error;
+}
+
 static int append_subject(
 	git_str *out,
 	size_t patch_idx,
@@ -117,14 +131,12 @@ static int append_header(
 	git_email_create_options *opts)
 {
 	char id[GIT_OID_HEXSZ];
-	char date[GIT_DATE_RFC2822_SZ];
 	int error;
 
 	if ((error = git_oid_fmt(id, commit_id)) < 0 ||
 	    (error = git_str_printf(out, "From %.*s %s\n", GIT_OID_HEXSZ, id, EMAIL_TIMESTAMP)) < 0 ||
 	    (error = git_str_printf(out, "From: %s <%s>\n", author->name, author->email)) < 0 ||
-	    (error = git__date_rfc2822_fmt(date, sizeof(date), &author->when)) < 0 ||
-	    (error = git_str_printf(out, "Date: %s\n", date)) < 0 ||
+	    (error = append_date(out, &author->when)) < 0 ||
 	    (error = append_subject(out, patch_idx, patch_count, summary, opts)) < 0)
 		return error;
 
diff --git a/src/revparse.c b/src/revparse.c
index cf39936..52dd072 100644
--- a/src/revparse.c
+++ b/src/revparse.c
@@ -11,6 +11,7 @@
 #include "tree.h"
 #include "refdb.h"
 #include "regexp.h"
+#include "date.h"
 
 #include "git2.h"
 
@@ -344,7 +345,7 @@ static int handle_at_syntax(git_object **out, git_reference **ref, const char *s
 		goto cleanup;
 	}
 
-	if (git__date_parse(&timestamp, curly_braces_content) < 0)
+	if (git_date_parse(&timestamp, curly_braces_content) < 0)
 		goto cleanup;
 
 	error = retrieve_revobject_from_reflog(out, ref, repo, git_str_cstr(&identifier), (size_t)timestamp);
diff --git a/src/util.h b/src/util.h
index 30cdd0d..141779a 100644
--- a/src/util.h
+++ b/src/util.h
@@ -37,8 +37,6 @@
 # define GIT_CONTAINER_OF(ptr, type, member) (type *)(ptr)
 #endif
 
-#define GIT_DATE_RFC2822_SZ  32
-
 /**
  * Return the length of a constant string.
  * We are aware that `strlen` performs the same task and is usually
@@ -295,26 +293,6 @@ GIT_INLINE(bool) git__isxdigit(int c)
 extern int git__parse_bool(int *out, const char *value);
 
 /*
- * Parse a string into a value as a git_time_t.
- *
- * Sample valid input:
- * - "yesterday"
- * - "July 17, 2003"
- * - "2003-7-17 08:23"
- */
-extern int git__date_parse(git_time_t *out, const char *date);
-
-/*
- * Format a git_time as a RFC2822 string
- *
- * @param out buffer to store formatted date; a '\\0' terminator will automatically be added.
- * @param len size of the buffer; should be atleast `GIT_DATE_RFC2822_SZ` in size;
- * @param date the date to be formatted
- * @return 0 if successful; -1 on error
- */
-extern int git__date_rfc2822_fmt(char *out, size_t len, const git_time *date);
-
-/*
  * Unescapes a string in-place.
  *
  * Edge cases behavior:
diff --git a/tests/date/date.c b/tests/date/date.c
index 88881d1..f70b4fe 100644
--- a/tests/date/date.c
+++ b/tests/date/date.c
@@ -1,6 +1,6 @@
 #include "clar_libgit2.h"
 
-#include "util.h"
+#include "date.h"
 
 void test_date_date__overflow(void)
 {
@@ -8,8 +8,8 @@ void test_date_date__overflow(void)
    git_time_t d2038, d2039;
 
    /* This is expected to fail on a 32-bit machine. */
-   cl_git_pass(git__date_parse(&d2038, "2038-1-1"));
-   cl_git_pass(git__date_parse(&d2039, "2039-1-1"));
+   cl_git_pass(git_date_parse(&d2038, "2038-1-1"));
+   cl_git_pass(git_date_parse(&d2039, "2039-1-1"));
    cl_assert(d2038 < d2039);
 #endif
 }
diff --git a/tests/date/rfc2822.c b/tests/date/rfc2822.c
index d98c1f0..b0bbcfc 100644
--- a/tests/date/rfc2822.c
+++ b/tests/date/rfc2822.c
@@ -1,40 +1,37 @@
 #include "clar_libgit2.h"
 
-#include "util.h"
+#include "date.h"
 
 void test_date_rfc2822__format_rfc2822_no_offset(void)
 {
 	git_time t = {1397031663, 0};
-	char buf[GIT_DATE_RFC2822_SZ];
+	git_str buf = GIT_STR_INIT;
 
-	cl_git_pass(git__date_rfc2822_fmt(buf, sizeof(buf), &t));
-	cl_assert(strcmp(buf, "Wed, 9 Apr 2014 08:21:03 +0000") == 0);
+	cl_git_pass(git_date_rfc2822_fmt(&buf, t.time, t.offset));
+	cl_assert_equal_s("Wed, 9 Apr 2014 08:21:03 +0000", buf.ptr);
+
+	git_str_dispose(&buf);
 }
 
 void test_date_rfc2822__format_rfc2822_positive_offset(void)
 {
 	git_time t = {1397031663, 120};
-	char buf[GIT_DATE_RFC2822_SZ];
+	git_str buf = GIT_STR_INIT;
+
+	cl_git_pass(git_date_rfc2822_fmt(&buf, t.time, t.offset));
+	cl_assert_equal_s("Wed, 9 Apr 2014 10:21:03 +0200", buf.ptr);
 
-	cl_git_pass(git__date_rfc2822_fmt(buf, sizeof(buf), &t));
-	cl_assert(strcmp(buf, "Wed, 9 Apr 2014 10:21:03 +0200") == 0);
+	git_str_dispose(&buf);
 }
 
 void test_date_rfc2822__format_rfc2822_negative_offset(void)
 {
 	git_time t = {1397031663, -120};
-	char buf[GIT_DATE_RFC2822_SZ];
+	git_str buf = GIT_STR_INIT;
 
-	cl_git_pass(git__date_rfc2822_fmt(buf, sizeof(buf), &t));
-	cl_assert(strcmp(buf, "Wed, 9 Apr 2014 06:21:03 -0200") == 0);
-}
-
-void test_date_rfc2822__format_rfc2822_buffer_too_small(void)
-{
-	/* "Wed, 10 Apr 2014 08:21:03 +0000" */
-	git_time t = {1397031663 + 86400, 0};
-	char buf[GIT_DATE_RFC2822_SZ-1];
+	cl_git_pass(git_date_rfc2822_fmt(&buf, t.time, t.offset));
+	cl_assert_equal_s("Wed, 9 Apr 2014 06:21:03 -0200", buf.ptr);
 
-	cl_git_fail(git__date_rfc2822_fmt(buf, sizeof(buf), &t));
+	git_str_dispose(&buf);
 }