From 74e1079df0cc6e8932e487455177a69f782b863a Mon Sep 17 00:00:00 2001

From: Greg Hudson <ghudson@mit.edu>

Date: Thu, 4 Jan 2018 14:35:12 -0500

Subject: [PATCH] Add k5_buf_add_vfmt to k5buf interface

(cherry picked from commit f05766469efc2a055085c0bcf9d40c4cdf47fe36)

---

 src/include/k5-buf.h                          |  8 ++++++

 src/util/support/k5buf.c                      | 26 +++++++++++--------

 src/util/support/libkrb5support-fixed.exports |  1 +

 3 files changed, 24 insertions(+), 11 deletions(-)

diff --git a/src/include/k5-buf.h b/src/include/k5-buf.h

index f3207bd09..1223916a6 100644

--- a/src/include/k5-buf.h

+++ b/src/include/k5-buf.h

@@ -76,6 +76,14 @@ void k5_buf_add_fmt(struct k5buf *buf, const char *fmt, ...)

 #endif

     ;

+/* Add sprintf-style formatted data to BUF, with a va_list.  The value of ap is

+ * undefined after the call. */

+void k5_buf_add_vfmt(struct k5buf *buf, const char *fmt, va_list ap)

+#if !defined(__cplusplus) && (__GNUC__ > 2)

+    __attribute__((__format__(__printf__, 2, 0)))

+#endif

+    ;

+

 /* Extend the length of buf by len and return a pointer to the reserved space,

  * to be filled in by the caller.  Return NULL on error. */

 void *k5_buf_get_space(struct k5buf *buf, size_t len);

diff --git a/src/util/support/k5buf.c b/src/util/support/k5buf.c

index f619f6a48..35978f238 100644

--- a/src/util/support/k5buf.c

+++ b/src/util/support/k5buf.c

@@ -141,9 +141,9 @@ k5_buf_add_len(struct k5buf *buf, const void *data, size_t len)

 }

 void

-k5_buf_add_fmt(struct k5buf *buf, const char *fmt, ...)

+k5_buf_add_vfmt(struct k5buf *buf, const char *fmt, va_list ap)

 {

-    va_list ap;

+    va_list apcopy;

     int r;

     size_t remaining;

     char *tmp;

@@ -154,9 +154,7 @@ k5_buf_add_fmt(struct k5buf *buf, const char *fmt, ...)

     if (buf->buftype == K5BUF_FIXED) {

         /* Format the data directly into the fixed buffer. */

-        va_start(ap, fmt);

         r = vsnprintf(endptr(buf), remaining, fmt, ap);

-        va_end(ap);

         if (SNPRINTF_OVERFLOW(r, remaining))

             set_error(buf);

         else

@@ -166,9 +164,9 @@ k5_buf_add_fmt(struct k5buf *buf, const char *fmt, ...)

     /* Optimistically format the data directly into the dynamic buffer. */

     assert(buf->buftype == K5BUF_DYNAMIC);

-    va_start(ap, fmt);

-    r = vsnprintf(endptr(buf), remaining, fmt, ap);

-    va_end(ap);

+    va_copy(apcopy, ap);

+    r = vsnprintf(endptr(buf), remaining, fmt, apcopy);

+    va_end(apcopy);

     if (!SNPRINTF_OVERFLOW(r, remaining)) {

         buf->len += (unsigned int) r;

         return;

@@ -179,9 +177,7 @@ k5_buf_add_fmt(struct k5buf *buf, const char *fmt, ...)

         if (!ensure_space(buf, r))

             return;

         remaining = buf->space - buf->len;

-        va_start(ap, fmt);

         r = vsnprintf(endptr(buf), remaining, fmt, ap);

-        va_end(ap);

         if (SNPRINTF_OVERFLOW(r, remaining))  /* Shouldn't ever happen. */

             k5_buf_free(buf);

         else

@@ -191,9 +187,7 @@ k5_buf_add_fmt(struct k5buf *buf, const char *fmt, ...)

     /* It's a pre-C99 snprintf implementation, or something else went wrong.

      * Fall back to asprintf. */

-    va_start(ap, fmt);

     r = vasprintf(&tmp, fmt, ap);

-    va_end(ap);

     if (r < 0) {

         k5_buf_free(buf);

         return;

@@ -206,6 +200,16 @@ k5_buf_add_fmt(struct k5buf *buf, const char *fmt, ...)

     free(tmp);

 }

+void

+k5_buf_add_fmt(struct k5buf *buf, const char *fmt, ...)

+{

+    va_list ap;

+

+    va_start(ap, fmt);

+    k5_buf_add_vfmt(buf, fmt, ap);

+    va_end(ap);

+}

+

 void *

 k5_buf_get_space(struct k5buf *buf, size_t len)

 {

diff --git a/src/util/support/libkrb5support-fixed.exports b/src/util/support/libkrb5support-fixed.exports

index 30c946e7e..cb9bf0826 100644

--- a/src/util/support/libkrb5support-fixed.exports

+++ b/src/util/support/libkrb5support-fixed.exports

@@ -6,6 +6,7 @@ k5_buf_init_dynamic

 k5_buf_add

 k5_buf_add_len

 k5_buf_add_fmt

+k5_buf_add_vfmt

 k5_buf_get_space

 k5_buf_truncate

 k5_buf_status