[dd260aaf72] Allow the -dictionary option to be read from a pushed transform.

3 files changed, 47 insertions, 27 deletions

diff --git a/doc/zlib.n b/doc/zlib.n
index 9f3078d..fd29e0d 100644
--- a/doc/zlib.n
+++ b/doc/zlib.n
@@ -174,7 +174,11 @@ to the \fBzlib push\fR command:
 .VS "TIP 400"
 Sets the compression dictionary to use when working with compressing or
 decompressing the data to be \fIbinData\fR. Not valid for transformations that
-work with gzip-format data.
+work with gzip-format data.  The dictionary should consist of strings (byte
+sequences) that are likely to be encountered later in the data to be compressed,
+with the most commonly used strings preferably put towards the end of the
+dictionary. Tcl provides no mechanism for choosing a good such dictionary for
+a particular data sequence.
 .VE
 .TP
 \fB\-header\fI dictionary\fR
@@ -207,11 +211,13 @@ compression algorithm depends on what format is being produced or consumed.
 .TP
 \fB\-dictionary\fI binData\fR
 .VS "TIP 400"
-This read-write options gets or sets the compression dictionary to use when
-working with compressing or decompressing the data to be \fIbinData\fR. It is
-not valid for transformations that work with gzip-format data, and should not
-normally be set on compressing transformations other than at the point where
-the transformation is stacked.
+This read-write options gets or sets the initial compression dictionary to use
+when working with compressing or decompressing the data to be \fIbinData\fR.
+It is not valid for transformations that work with gzip-format data, and should
+not normally be set on compressing transformations other than at the point where
+the transformation is stacked. Note that this cannot be used to get the
+current active compression dictionary mid-stream, as that information is not
+exposed by the underlying library.
 .VE
 .TP
 \fB\-flush\fI type\fR
diff --git a/generic/tclZlib.c b/generic/tclZlib.c
index 691d57a..dac47cf 100644
--- a/generic/tclZlib.c
+++ b/generic/tclZlib.c
@@ -2906,9 +2906,9 @@ ZlibTransformClose(
 		}
 	    }
 	} while (e != Z_STREAM_END);
-	e = deflateEnd(&cd->outStream);
+	(void) deflateEnd(&cd->outStream);
     } else {
-	e = inflateEnd(&cd->inStream);
+	(void) inflateEnd(&cd->inStream);
     }
 
     /*
@@ -3344,10 +3344,13 @@ ZlibTransformGetOption(
 		Tcl_DStringAppendElement(dsPtr, "");
 	    }
 	} else {
-	    int len;
-	    const char *str = Tcl_GetStringFromObj(cd->compDictObj, &len);
+	    if (cd->compDictObj) {
+		int len;
+		const char *str = Tcl_GetStringFromObj(cd->compDictObj, &len);
 
-	    Tcl_DStringAppend(dsPtr, str, len);
+		Tcl_DStringAppend(dsPtr, str, len);
+	    }
+	    return TCL_OK;
 	}
     }
 
@@ -3549,7 +3552,6 @@ ZlibStackChannelTransform(
     ZlibChannelData *cd = ckalloc(sizeof(ZlibChannelData));
     Tcl_Channel chan;
     int wbits = 0;
-    int e;
 
     if (mode != TCL_ZLIB_STREAM_DEFLATE && mode != TCL_ZLIB_STREAM_INFLATE) {
 	Tcl_Panic("unknown mode: %d", mode);
@@ -3603,43 +3605,35 @@ ZlibStackChannelTransform(
      */
 
     if (mode == TCL_ZLIB_STREAM_INFLATE) {
-	e = inflateInit2(&cd->inStream, wbits);
-	if (e != Z_OK) {
+	if (inflateInit2(&cd->inStream, wbits) != Z_OK) {
 	    goto error;
 	}
 	cd->inAllocated = DEFAULT_BUFFER_SIZE;
 	cd->inBuffer = ckalloc(cd->inAllocated);
 	if (cd->flags & IN_HEADER) {
-	    e = inflateGetHeader(&cd->inStream, &cd->inHeader.header);
-	    if (e != Z_OK) {
+	    if (inflateGetHeader(&cd->inStream, &cd->inHeader.header) != Z_OK) {
 		goto error;
 	    }
 	}
 	if (cd->format == TCL_ZLIB_FORMAT_RAW && cd->compDictObj) {
-	    e = SetInflateDictionary(&cd->inStream, cd->compDictObj);
-	    if (e != Z_OK) {
+	    if (SetInflateDictionary(&cd->inStream, cd->compDictObj) != Z_OK) {
 		goto error;
 	    }
-	    TclDecrRefCount(cd->compDictObj);
-	    cd->compDictObj = NULL;
 	}
     } else {
-	e = deflateInit2(&cd->outStream, level, Z_DEFLATED, wbits,
-		MAX_MEM_LEVEL, Z_DEFAULT_STRATEGY);
-	if (e != Z_OK) {
+	if (deflateInit2(&cd->outStream, level, Z_DEFLATED, wbits,
+		MAX_MEM_LEVEL, Z_DEFAULT_STRATEGY) != Z_OK) {
 	    goto error;
 	}
 	cd->outAllocated = DEFAULT_BUFFER_SIZE;
 	cd->outBuffer = ckalloc(cd->outAllocated);
 	if (cd->flags & OUT_HEADER) {
-	    e = deflateSetHeader(&cd->outStream, &cd->outHeader.header);
-	    if (e != Z_OK) {
+	    if (deflateSetHeader(&cd->outStream, &cd->outHeader.header) != Z_OK) {
 		goto error;
 	    }
 	}
 	if (cd->compDictObj) {
-	    e = SetDeflateDictionary(&cd->outStream, cd->compDictObj);
-	    if (e != Z_OK) {
+	    if (SetDeflateDictionary(&cd->outStream, cd->compDictObj) != Z_OK) {
 		goto error;
 	    }
 	}
diff --git a/tests/zlib.test b/tests/zlib.test
index 968469d..c9e5f10 100644
--- a/tests/zlib.test
+++ b/tests/zlib.test
@@ -401,6 +401,26 @@ test zlib-8.16 {Bug 3603553: buffer transfer with large writes} -setup {
 } -cleanup {
     removeFile $file
 } -result 57647
+test zlib-8.17 {Bug dd260aaf: fconfigure} -setup {
+    lassign [chan pipe] inSide outSide
+} -constraints zlib -body {
+    zlib push inflate $inSide
+    zlib push deflate $outSide
+    list [chan configure $inSide -dictionary] [chan configure $outSide -dictionary]
+} -cleanup {
+    catch {close $inSide}
+    catch {close $outSide}
+} -result {{} {}}
+test zlib-8.18 {Bug dd260aaf: fconfigure} -setup {
+    lassign [chan pipe] inSide outSide
+} -constraints zlib -body {
+    zlib push inflate $inSide -dictionary "one two"
+    zlib push deflate $outSide -dictionary "one two"
+    list [chan configure $inSide -dictionary] [chan configure $outSide -dictionary]
+} -cleanup {
+    catch {close $inSide}
+    catch {close $outSide}
+} -result {{one two} {one two}}
 
 test zlib-9.1 "check fcopy with push" -constraints zlib -setup {
     set sfile [makeFile {} testsrc.gz]