From 6fad35c6a13919db9ab3b4f768f624220da50426 Mon Sep 17 00:00:00 2001
From: Binh Vo <binhvo@fb.com>
Date: Wed, 9 Jun 2021 16:49:36 -0400
Subject: [PATCH] Add support for negative levels in --adapt=min and
 --adapt=max"

---
 programs/zstdcli.c | 21 +++++++++++++++++++--
 tests/playTests.sh |  1 +
 2 files changed, 20 insertions(+), 2 deletions(-)

diff --git a/programs/zstdcli.c b/programs/zstdcli.c
index 9e2133c4..c3a6ae0b 100644
--- a/programs/zstdcli.c
+++ b/programs/zstdcli.c
@@ -354,6 +354,23 @@ static unsigned readU32FromChar(const char** stringPtr) {
     return result;
 }
 
+/*! readIntFromChar() :
+ * @return : signed integer value read from input in `char` format.
+ *  allows and interprets K, KB, KiB, M, MB and MiB suffix.
+ *  Will also modify `*stringPtr`, advancing it to position where it stopped reading.
+ *  Note : function will exit() program if digit sequence overflows */
+static int readIntFromChar(const char** stringPtr) {
+    static const char errorMsg[] = "error: numeric value overflows 32-bit int";
+    int sign = 1;
+    unsigned result;
+    if (**stringPtr=='-') {
+        (*stringPtr)++;
+        sign = -1;
+    }
+    if (readU32FromCharChecked(stringPtr, &result)) { errorOut(errorMsg); }
+    return (int) result * sign;
+}
+
 /*! readSizeTFromCharChecked() :
  * @return 0 if success, and store the result in *value.
  *  allows and interprets K, KB, KiB, M, MB and MiB suffix.
@@ -547,8 +564,8 @@ static ZDICT_fastCover_params_t defaultFastCoverParams(void)
 static unsigned parseAdaptParameters(const char* stringPtr, int* adaptMinPtr, int* adaptMaxPtr)
 {
     for ( ; ;) {
-        if (longCommandWArg(&stringPtr, "min=")) { *adaptMinPtr = (int)readU32FromChar(&stringPtr); if (stringPtr[0]==',') { stringPtr++; continue; } else break; }
-        if (longCommandWArg(&stringPtr, "max=")) { *adaptMaxPtr = (int)readU32FromChar(&stringPtr); if (stringPtr[0]==',') { stringPtr++; continue; } else break; }
+        if (longCommandWArg(&stringPtr, "min=")) { *adaptMinPtr = readIntFromChar(&stringPtr); if (stringPtr[0]==',') { stringPtr++; continue; } else break; }
+        if (longCommandWArg(&stringPtr, "max=")) { *adaptMaxPtr = readIntFromChar(&stringPtr); if (stringPtr[0]==',') { stringPtr++; continue; } else break; }
         DISPLAYLEVEL(4, "invalid compression parameter \n");
         return 0;
     }
diff --git a/tests/playTests.sh b/tests/playTests.sh
index 25293900..380e148f 100755
--- a/tests/playTests.sh
+++ b/tests/playTests.sh
@@ -1519,6 +1519,7 @@ then
     println "\n===>   adaptive mode "
     roundTripTest -g270000000 " --adapt"
     roundTripTest -g27000000 " --adapt=min=1,max=4"
+    roundTripTest -g27000000 " --adapt=min=-2,max=-1"
     println "===>   test: --adapt must fail on incoherent bounds "
     datagen > tmp
     zstd -f -vv --adapt=min=10,max=9 tmp && die "--adapt must fail on incoherent bounds"