From: Olivier Perret <Olivier.Perret@mailbox.org>
Date: Wed, 12 May 2021 20:11:15 +0000 (+0200)
Subject: fileio: clamp value of windowLog in patch-mode (#2637)
X-Git-Tag: v1.5.0^2~5
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=d4548c96cb073a575eb616cdff1a95d12f631547;p=thirdparty%2Fzstd.git

fileio: clamp value of windowLog in patch-mode (#2637)

With small enough input files, the inferred value of fileWindowLog could
be smaller than ZSTD_WINDOWLOG_MIN.

This can be reproduced like so:
$ echo abc > small
$ echo abcdef > small2
$ zstd --patch-from small small2 -o patch
previously, this would fail with the error "zstd: error 11 : Parameter is out of bound"
---

diff --git a/programs/fileio.c b/programs/fileio.c
index ec9390839..5693ac399 100644
--- a/programs/fileio.c
+++ b/programs/fileio.c
@@ -951,7 +951,7 @@ static void FIO_adjustParamsForPatchFromMode(FIO_prefs_t* const prefs,
     FIO_adjustMemLimitForPatchFromMode(prefs, dictSize, maxSrcFileSize);
     if (fileWindowLog > ZSTD_WINDOWLOG_MAX)
         DISPLAYLEVEL(1, "Max window log exceeded by file (compression ratio will suffer)\n");
-    comprParams->windowLog = MIN(ZSTD_WINDOWLOG_MAX, fileWindowLog);
+    comprParams->windowLog = MAX(ZSTD_WINDOWLOG_MIN, MIN(ZSTD_WINDOWLOG_MAX, fileWindowLog));
     if (fileWindowLog > ZSTD_cycleLog(cParams.chainLog, cParams.strategy)) {
         if (!prefs->ldmFlag)
             DISPLAYLEVEL(1, "long mode automatically triggered\n");