liblzma: Clarify a comment.

diff --git a/src/liblzma/lzma/lzma_decoder.c b/src/liblzma/lzma/lzma_decoder.c
index f7323061315086147fcf3d9723f621b8eecdfe0c..6c9cbe22d0fc54eb7f6162c088240b3a21c2b145 100644 (file)
--- a/src/liblzma/lzma/lzma_decoder.c
+++ b/src/liblzma/lzma/lzma_decoder.c
@@ -338,9 +338,12 @@ lzma_decode(void *coder_ptr, lzma_dict *restrict dictptr,
                // Non-resumable Mode (fast) //
                ///////////////////////////////
 
-               // If there is not enough room for another LZMA symbol
-               // go to Resumable mode.
-               if (unlikely(!rc_is_fast_allowed() || dict.pos == dict.limit))
+               // Go to Resumable mode (1) if there is not enough input to
+               // safely decode any possible LZMA symbol or (2) if the
+               // dictionary is full, which may need special checks that
+               // are only done in the Resumable mode.
+               if (unlikely(!rc_is_fast_allowed()
+                               || dict.pos == dict.limit))
                        goto slow;
 
                // Decode the first bit from the next LZMA symbol.