From: Timo Sirainen <timo.sirainen@open-xchange.com>
Date: Tue, 3 Feb 2026 12:25:37 +0000 (+0200)
Subject: lib: Add buffer_nul_terminate()
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=035e31b6c42a2d66ed2badd0fb5236bd47e49b92;p=thirdparty%2Fdovecot%2Fcore.git

lib: Add buffer_nul_terminate()
---

diff --git a/src/lib/buffer.c b/src/lib/buffer.c
index c85f1e61db..76535828b0 100644
--- a/src/lib/buffer.c
+++ b/src/lib/buffer.c
@@ -348,6 +348,18 @@ void buffer_insert_zero(buffer_t *_buf, size_t pos, size_t data_size)
 	}
 }
 
+void buffer_nul_terminate(buffer_t *_buf)
+{
+	struct real_buffer *buf = container_of(_buf, struct real_buffer, buf);
+
+	/* +1 extra byte is always kept for NUL termination */
+	i_assert(buf->used < buf->alloc);
+	/* Buffer might not be writable, so check first if the NUL is
+	   already there. */
+	if (((const char *)buf->r_buffer)[buf->used] != '\0')
+		buf->w_buffer[buf->used] = '\0';
+}
+
 void buffer_copy(buffer_t *_dest, size_t dest_pos,
 		 const buffer_t *_src, size_t src_pos, size_t copy_size)
 {
diff --git a/src/lib/buffer.h b/src/lib/buffer.h
index c5eef4bf5f..c2c1ced3ca 100644
--- a/src/lib/buffer.h
+++ b/src/lib/buffer.h
@@ -84,6 +84,9 @@ void buffer_replace(buffer_t *buf, size_t pos, size_t size,
 void buffer_write_zero(buffer_t *buf, size_t pos, size_t data_size);
 void buffer_append_zero(buffer_t *buf, size_t data_size);
 void buffer_insert_zero(buffer_t *buf, size_t pos, size_t data_size);
+/* Terminate the buffer with a NUL character after the buffer's used size.
+   The NUL will not be included in the used size. */
+void buffer_nul_terminate(buffer_t *buf);
 
 /* Copy data from buffer to another. The buffers may be same in which case
    it's internal copying, possibly with overlapping positions (ie. memmove()