From 5245e701247fd4691c197151b9551c65e2af0213 Mon Sep 17 00:00:00 2001 From: dkf Date: Mon, 11 Feb 2013 08:11:28 +0000 Subject: [Bug 3603553]: Ensure that data gets written to the underlying stream by compressing transforms when the amount of data to be written is one buffer's-worth; problem was particularly likely to occur when compressing large quantities of not-very-compressible data. Many thanks to Piera Poggio (vampiera) for reporting. --- ChangeLog | 9 +++++++++ generic/tclZlib.c | 2 +- tests/zlib.test | 19 +++++++++++++++++++ 3 files changed, 29 insertions(+), 1 deletion(-) diff --git a/ChangeLog b/ChangeLog index 743c571..64d80c1 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,12 @@ +2013-02-11 Donal K. Fellows + + * generic/tclZlib.c (ZlibTransformOutput): [Bug 3603553]: Ensure that + data gets written to the underlying stream by compressing transforms + when the amount of data to be written is one buffer's-worth; problem + was particularly likely to occur when compressing large quantities of + not-very-compressible data. Many thanks to Piera Poggio (vampiera) for + reporting. + 2013-02-09 Donal K. Fellows * generic/tclOOBasic.c (TclOO_Object_VarName): [Bug 3603695]: Change diff --git a/generic/tclZlib.c b/generic/tclZlib.c index 47091de..ff887c8 100644 --- a/generic/tclZlib.c +++ b/generic/tclZlib.c @@ -3111,7 +3111,7 @@ ZlibTransformOutput( e = deflate(&cd->outStream, Z_NO_FLUSH); produced = cd->outAllocated - cd->outStream.avail_out; - if (e == Z_OK && cd->outStream.avail_out > 0) { + if (e == Z_OK && produced > 0) { if (Tcl_WriteRaw(cd->parent, cd->outBuffer, produced) < 0) { *errorCodePtr = Tcl_GetErrno(); return -1; diff --git a/tests/zlib.test b/tests/zlib.test index 891dba0..96914ca 100644 --- a/tests/zlib.test +++ b/tests/zlib.test @@ -366,6 +366,25 @@ test zlib-8.15 {transformtion and fconfigure} -setup { catch {close $inSide} catch {$strm close} } -result {358 358} +test zlib-8.16 {Bug 3603553: buffer transfer with large writes} -setup { + # Actual data isn't very important; needs to be substantially larger than + # the internal buffer (8kB) and incompressible. + set largeData {} + for {set i 0;expr srand(1)} {$i < 100000} {incr i} { + append largeData [lindex "a b c d e f g h i j k l m n o p" \ + [expr {int(16*rand())}]] + } + set file [makeFile {} test.gz] +} -constraints zlib -body { + set f [open $file wb] + fconfigure $f -buffering none + zlib push gzip $f + puts -nonewline $f $largeData + close $f + file size $file +} -cleanup { + removeFile $file +} -result 57647 test zlib-9.1 "check fcopy with push" -constraints zlib -setup { set sfile [makeFile {} testsrc.gz] -- cgit v0.12