Avoid internal error with --format=xz --lzma1.

diff --git a/src/xz/coder.c b/src/xz/coder.c
index 90c9927..7cf6186 100644 (file)
--- a/src/xz/coder.c
+++ b/src/xz/coder.c
@@ -151,12 +151,20 @@ coder_set_compression_settings(void)
        // Terminate the filter options array.
        filters[filters_count].id = LZMA_VLI_UNKNOWN;
 
-       // If we are using the LZMA_Alone format, allow exactly one filter
-       // which has to be LZMA.
+       // If we are using the .lzma format, allow exactly one filter
+       // which has to be LZMA1.
        if (opt_format == FORMAT_LZMA && (filters_count != 1
                        || filters[0].id != LZMA_FILTER_LZMA1))
-               message_fatal(_("With --format=lzma only the LZMA1 filter "
-                               "is supported"));
+               message_fatal(_("The .lzma format supports only "
+                               "the LZMA1 filter"));
+
+       // If we are using the .xz format, make sure that there is no LZMA1
+       // filter to prevent LZMA_PROG_ERROR.
+       if (opt_format == FORMAT_XZ)
+               for (size_t i = 0; i < filters_count; ++i)
+                       if (filters[i].id == LZMA_FILTER_LZMA1)
+                               message_fatal(_("LZMA1 cannot be used "
+                                               "with the .xz format"));
 
        // Print the selected filter chain.
        message_filters(V_DEBUG, filters);