Avoid undefined negation behavior if windowBits is INT_MIN.

Mark Adler · Mark Adler · commit a9e14e85415e · 2022-10-06T20:43:18.000-07:00
diff --git a/deflate.c b/deflate.c
@@ -279,6 +279,8 @@ int ZEXPORT deflateInit2_(strm, level, method, windowBits, memLevel, strategy,
 
     if (windowBits < 0) { /* suppress zlib wrapper */
         wrap = 0;
+        if (windowBits < -15)
+            return Z_STREAM_ERROR;
         windowBits = -windowBits;
     }
 #ifdef GZIP
diff --git a/inflate.c b/inflate.c
@@ -168,6 +168,8 @@ int windowBits;
 
     /* extract wrap request from windowBits parameter */
     if (windowBits < 0) {
+        if (windowBits < -15)
+            return Z_STREAM_ERROR;
         wrap = 0;
         windowBits = -windowBits;
     }

Original file line number	Diff line number	Diff line change
`@@ -279,6 +279,8 @@ int ZEXPORT deflateInit2_(strm, level, method, windowBits, memLevel, strategy,`
`279`	`279`
`280`	`280`	`if (windowBits < 0) { /* suppress zlib wrapper */`
`281`	`281`	`wrap = 0;`
	`282`	`+ if (windowBits < -15)`
	`283`	`+ return Z_STREAM_ERROR;`
`282`	`284`	`windowBits = -windowBits;`
`283`	`285`	`}`
`284`	`286`	`#ifdef GZIP`
Original file line number	Diff line number	Diff line change
`@@ -168,6 +168,8 @@ int windowBits;`
`168`	`168`
`169`	`169`	`/* extract wrap request from windowBits parameter */`
`170`	`170`	`if (windowBits < 0) {`
	`171`	`+ if (windowBits < -15)`
	`172`	`+ return Z_STREAM_ERROR;`
`171`	`173`	`wrap = 0;`
`172`	`174`	`windowBits = -windowBits;`
`173`	`175`	`}`