Merge branch 'rs/vsnprintf-failure-is-not-a-bug'

Demote a BUG() to an die() when the failure from vsnprintf() may
not be due to a programmer error.

* rs/vsnprintf-failure-is-not-a-bug:
  don't report vsnprintf(3) error as bug
diff --git a/mem-pool.c b/mem-pool.c
index 3065b12..a3ba388 100644
--- a/mem-pool.c
+++ b/mem-pool.c
@@ -4,6 +4,7 @@
 
 #include "git-compat-util.h"
 #include "mem-pool.h"
+#include "gettext.h"
 
 #define BLOCK_GROWTH_SIZE (1024 * 1024 - sizeof(struct mp_block))
 
@@ -122,7 +123,7 @@ static char *mem_pool_strvfmt(struct mem_pool *pool, const char *fmt,
 	len = vsnprintf(next_free, available, fmt, cp);
 	va_end(cp);
 	if (len < 0)
-		BUG("your vsnprintf is broken (returned %d)", len);
+		die(_("unable to format message: %s"), fmt);
 
 	size = st_add(len, 1); /* 1 for NUL */
 	ret = mem_pool_alloc(pool, size);
diff --git a/strbuf.c b/strbuf.c
index 1492a08..0d929e4 100644
--- a/strbuf.c
+++ b/strbuf.c
@@ -277,7 +277,7 @@ void strbuf_vinsertf(struct strbuf *sb, size_t pos, const char *fmt, va_list ap)
 	len = vsnprintf(sb->buf + sb->len, 0, fmt, cp);
 	va_end(cp);
 	if (len < 0)
-		BUG("your vsnprintf is broken (returned %d)", len);
+		die(_("unable to format message: %s"), fmt);
 	if (!len)
 		return; /* nothing to do */
 	if (unsigned_add_overflows(sb->len, len))
@@ -404,7 +404,7 @@ void strbuf_vaddf(struct strbuf *sb, const char *fmt, va_list ap)
 	len = vsnprintf(sb->buf + sb->len, sb->alloc - sb->len, fmt, cp);
 	va_end(cp);
 	if (len < 0)
-		BUG("your vsnprintf is broken (returned %d)", len);
+		die(_("unable to format message: %s"), fmt);
 	if (len > strbuf_avail(sb)) {
 		strbuf_grow(sb, len);
 		len = vsnprintf(sb->buf + sb->len, sb->alloc - sb->len, fmt, ap);
diff --git a/wrapper.c b/wrapper.c
index eeac374..f87d90b 100644
--- a/wrapper.c
+++ b/wrapper.c
@@ -670,7 +670,7 @@ int xsnprintf(char *dst, size_t max, const char *fmt, ...)
 	va_end(ap);
 
 	if (len < 0)
-		BUG("your snprintf is broken");
+		die(_("unable to format message: %s"), fmt);
 	if (len >= max)
 		BUG("attempt to snprintf into too-small buffer");
 	return len;