Select the default integrity check type at runtime.

Previously it was set statically to CRC64 or CRC32
depending on options passed to the configure script.

1 files changed, 14 insertions, 5 deletions

diff --git a/src/xz/coder.c b/src/xz/coder.c
index e6ed3e55..cd5da299 100644
--- a/src/xz/coder.c
+++ b/src/xz/coder.c
@@ -56,17 +56,17 @@ static bool preset_default = true;
 static bool preset_extreme = false;
 
 /// Integrity check type
-#ifdef HAVE_CHECK_CRC64
-static lzma_check check = LZMA_CHECK_CRC64;
-#else
-static lzma_check check = LZMA_CHECK_CRC32;
-#endif
+static lzma_check check;
+
+/// This becomes false if the --check=CHECK option is used.
+static bool check_default = true;
 
 
 extern void
 coder_set_check(lzma_check new_check)
 {
 	check = new_check;
+	check_default = false;
 	return;
 }
 
@@ -265,6 +265,15 @@ coder_set_compression_settings(void)
 		opt_threads = thread_limit;
 */
 
+	if (check_default) {
+		// The default check type is CRC64, but fallback to CRC32
+		// if CRC64 isn't supported by the copy of liblzma we are
+		// using. CRC32 is always supported.
+		check = LZMA_CHECK_CRC64;
+		if (!lzma_check_is_supported(check))
+			check = LZMA_CHECK_CRC32;
+	}
+
 	return;
 }