[Bug 3390073]: Return the correct length of written data for a compressing

transform, ensuring that buffers are written exactly once instead of multiple
times or not at all (producing an invalid file).

3 files changed, 43 insertions, 6 deletions

diff --git a/ChangeLog b/ChangeLog
index 127ee0b..bb2632e 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,24 +1,29 @@
+2011-08-12  Donal K. Fellows  <dkf@users.sf.net>
+
+	* generic/tclZlib.c (ZlibTransformOutput): [Bug 3390073]: Return the
+	correct length of written data for a compressing transform.
+
 2011-08-10 Alexandre Ferrieux  <ferrieux@users.sourceforge.net>
 
-	* generic/tclTestObj.c: [Bug 3386721] Allow multiple [load]ing of
-	the Tcltest package
+	* generic/tclTestObj.c: [Bug 3386721]: Allow multiple [load]ing of the
+	Tcltest package.
 
 2011-08-09 Alexandre Ferrieux  <ferrieux@users.sourceforge.net>
 
-	* generic/tclBasic.c: [Bug 2919042] Restore "valgrindability" of Tcl
+	* generic/tclBasic.c: [Bug 2919042]: Restore "valgrindability" of Tcl
 	* generic/tclEvent.c: that was lost by the streamlining of [exit], by
 	* generic/tclExecute.c: conditionally forcing a full Finalize:
 	* generic/tclInt.h:  use -DPURIFY or ::env(TCL_FINALIZE_ON_EXIT)
 
 2011-08-09 Alexandre Ferrieux  <ferrieux@users.sourceforge.net>
 
-	* generic/tclCompCmds.c: [Bug 3386417] avoid a reference loop between
+	* generic/tclCompCmds.c: [Bug 3386417]: Avoid a reference loop between
 	* generic/tclInt.h:      the bytecode and its companion errostack
 	* generic/tclResult.c:   when compiling a syntax error.
 
 2011-08-09  Jan Nijtmans  <nijtmans@users.sf.net>
 
-	* win/tclWinConsole.c: [Bug 3388350] mingw64 compiler warnings
+	* win/tclWinConsole.c: [Bug 3388350]: mingw64 compiler warnings
 	* win/tclWinDde.c
 	* win/tclWinPipe.c
 	* win/tclWinSerial.c
diff --git a/generic/tclZlib.c b/generic/tclZlib.c
index be91365..81012dc 100644
--- a/generic/tclZlib.c
+++ b/generic/tclZlib.c
@@ -2460,7 +2460,7 @@ ZlibTransformOutput(
 	return -1;
     }
 
-    return toWrite - cd->outStream.avail_out;
+    return toWrite - cd->outStream.avail_in;
 }
 
 static int
diff --git a/tests/zlib.test b/tests/zlib.test
index 47eeab8..dac11e4 100644
--- a/tests/zlib.test
+++ b/tests/zlib.test
@@ -156,6 +156,7 @@ test zlib-8.3 {zlib transformation and fileevent} -constraints zlib -setup {
     close $srv
     removeFile $file
 } -result 81920-->81920
+
 test zlib-9.1 "check fcopy with push" -constraints zlib -setup {
     set sfile [makeFile {} testsrc.gz]
     set file [makeFile {} test.gz]
@@ -569,6 +570,37 @@ test zlib-10.2 "bug #2818131 (mismatch gets)" -constraints {
     rename bgerror {}
     rename zlibRead {}
 } -result {error {invalid block type}}
+
+test zlib-11.1 "Bug #3390073: mis-appled gzip filtering" -setup {
+    set file [makeFile {} test.input]
+} -constraints zlib -body {
+    set f [open $file wb]
+    puts -nonewline [zlib push gzip $f] [string repeat "hello" 1000]
+    close $f
+    set f [open $file rb]
+    set d [read $f]
+    close $f
+    set d [zlib gunzip $d]
+    list [regexp -all "hello" $d] [string length [regsub -all "hello" $d {}]]
+} -cleanup {
+    removeFile $file
+} -result {1000 0}
+test zlib-11.2 "Bug #3390073: mis-appled gzip filtering" -setup {
+    set file [makeFile {} test.input]
+} -constraints zlib -body {
+    set f [open $file wb]
+    puts -nonewline [zlib push gzip $f -header {filename /foo/bar}] \
+	[string repeat "hello" 1000]
+    close $f
+    set f [open $file rb]
+    set d [read $f]
+    close $f
+    set d [zlib gunzip $d -header h]
+    list [regexp -all "hello" $d] [dict get $h filename] \
+	[string length [regsub -all "hello" $d {}]]
+} -cleanup {
+    removeFile $file
+} -result {1000 /foo/bar 0}
 
 ::tcltest::cleanupTests
 return