libdpkg: Add new str_concat() function

4 files changed, 54 insertions, 1 deletions

diff --git a/lib/dpkg/libdpkg.map b/lib/dpkg/libdpkg.map
index 5e685c948..85b8a1fa6 100644
--- a/lib/dpkg/libdpkg.map
+++ b/lib/dpkg/libdpkg.map
@@ -90,6 +90,7 @@ LIBDPKG_PRIVATE {
 
 	str_match_end;
 	str_fnv_hash;
+	str_concat;
 	str_fmt;
 	str_escape_fmt;
 	str_strip_quotes;
diff --git a/lib/dpkg/string.c b/lib/dpkg/string.c
index 220e2789f..ff97159f9 100644
--- a/lib/dpkg/string.c
+++ b/lib/dpkg/string.c
@@ -28,6 +28,25 @@
 #include <dpkg/string.h>
 #include <dpkg/dpkg.h>
 
+char *
+str_concat(char *dst, ...)
+{
+	va_list args;
+	const char *src;
+	size_t len;
+
+	va_start(args, dst);
+	while ((src = va_arg(args, const char *))) {
+		len = strlen(src);
+		memcpy(dst, src, len);
+		dst += len;
+	}
+	va_end(args);
+	*dst = '\0';
+
+	return dst;
+}
+
 /**
  * Match the end of a string.
  *
diff --git a/lib/dpkg/string.h b/lib/dpkg/string.h
index 927aeaee4..d0f6bd7ad 100644
--- a/lib/dpkg/string.h
+++ b/lib/dpkg/string.h
@@ -56,6 +56,7 @@ bool str_match_end(const char *str, const char *end);
 
 unsigned int str_fnv_hash(const char *str);
 
+char *str_concat(char *dst, ...) DPKG_ATTR_SENTINEL;
 char *str_fmt(const char *fmt, ...) DPKG_ATTR_PRINTF(1);
 char *str_escape_fmt(char *dest, const char *src, size_t n);
 char *str_quote_meta(const char *src);
diff --git a/lib/dpkg/t/t-string.c b/lib/dpkg/t/t-string.c
index 038de84b0..1f5ee4cbe 100644
--- a/lib/dpkg/t/t-string.c
+++ b/lib/dpkg/t/t-string.c
@@ -77,6 +77,37 @@ test_str_fnv_hash(void)
 }
 
 static void
+test_str_concat(void)
+{
+	char buf[1024], *str;
+
+	memset(buf, 0, sizeof(buf));
+	str = str_concat(buf, NULL);
+	test_pass(str == buf);
+	test_str(buf, ==, "");
+
+	memset(buf, 0, sizeof(buf));
+	str = str_concat(buf, "aaa", NULL);
+	test_str(buf, ==, "aaa");
+	test_pass(str == buf + 3);
+
+	memset(buf, 0, sizeof(buf));
+	str = str_concat(buf, "zzzz", "yy", "xxxx", NULL);
+	test_str(buf, ==, "zzzzyyxxxx");
+	test_pass(str == buf + 10);
+
+	memset(buf, 0, sizeof(buf));
+	str = str_concat(buf, "1234", "", "5678", NULL);
+	test_str(buf, ==, "12345678");
+	test_pass(str == buf + 8);
+
+	memset(buf, ' ', sizeof(buf));
+	str = str_concat(buf, "eol", NULL, "bom", NULL);
+	test_str(buf, ==, "eol");
+	test_pass(str == buf + 3);
+}
+
+static void
 test_str_fmt(void)
 {
 	char *str;
@@ -197,11 +228,12 @@ test_str_strip_quotes(void)
 
 TEST_ENTRY(test)
 {
-	test_plan(50);
+	test_plan(60);
 
 	test_str_is_set();
 	test_str_match_end();
 	test_str_fnv_hash();
+	test_str_concat();
 	test_str_fmt();
 	test_str_escape_fmt();
 	test_str_quote_meta();