Bug [c4eb46a1]: endless loop on gets, non blocking, profile strict, encoding error: remove non-blocking exit condition and add test case

2 files changed, 33 insertions, 5 deletions

diff --git a/generic/tclIO.c b/generic/tclIO.c
index 6461909..c92fb64 100644
--- a/generic/tclIO.c
+++ b/generic/tclIO.c
@@ -4918,8 +4918,17 @@ Tcl_GetsObj(
 	    }
 	    goto gotEOL;
 	} else if (gs.bytesWrote == 0
-		&& GotFlag(statePtr, CHANNEL_ENCODING_ERROR)
-		&& !GotFlag(statePtr, CHANNEL_NONBLOCKING)) {
+		&& GotFlag(statePtr, CHANNEL_ENCODING_ERROR)) {
+	    /* Ticket c4eb46a1 Harald Oehlmann 2023-11-12 debugging session.
+	     * In non blocking mode we loop indifenitly on a decoding error in
+	     * this while-loop.
+	     * Removed the following from the upper condition:
+	     * "&& !GotFlag(statePtr, CHANNEL_NONBLOCKING)"
+	     * In case of an encoding error with leading correct bytes, we pass here
+	     * two times, as gs.bytesWrote is not 0 on the first pass. This feels
+	     * once to much, as the data is anyway not used.
+	     */
+	     
 	    /* Set eol to the position that caused the encoding error, and then
 	     * continue to gotEOL, which stores the data that was decoded
 	     * without error to objPtr.  This allows the caller to do something
diff --git a/tests/io.test b/tests/io.test
index 9f731ad..a6683c8 100644
--- a/tests/io.test
+++ b/tests/io.test
@@ -9193,7 +9193,7 @@ test io-75.5 {invalid utf-8 encoding read is ignored (-profile tcl8)} -setup {
     removeFile io-75.5
 } -result 4181
 
-test io-75.6 {invalid utf-8 encoding, gets is not ignored (-profile strict)} -setup {
+test io-75.6 {invalid utf-8 encoding, blocking gets is not ignored (-profile strict)} -setup {
     set fn [makeFile {} io-75.6]
     set f [open $fn w+]
     fconfigure $f -encoding binary
@@ -9211,6 +9211,25 @@ test io-75.6 {invalid utf-8 encoding, gets is not ignored (-profile strict)} -se
 } -match glob -returnCodes 1 -result {error reading "file*":\
 	invalid or incomplete multibyte or wide character}
 
+# TCL ticket c4eb46a196: non blocking case had endless loop, so test it
+test io-75.6.2 {invalid utf-8 encoding, non blocking gets is not ignored (-profile strict)} -setup {
+    set fn [makeFile {} io-75.6.2]
+    set f [open $fn w+]
+    fconfigure $f -encoding binary
+    # \x81 is an incomplete byte sequence in utf-8
+    puts -nonewline $f A\x81
+    flush $f
+    seek $f 0
+    fconfigure $f -encoding utf-8 -buffering none -eofchar {} \
+	    -translation lf -profile strict -blocking 0
+} -body {
+    gets $f
+} -cleanup {
+    close $f
+    removeFile io-75.6.2
+} -match glob -returnCodes 1 -result {error reading "file*":\
+	invalid or incomplete multibyte or wide character}
+
 test io-75.7 {
     invalid utf-8 encoding read is not ignored (-profile strict)
 } -setup {
@@ -9232,7 +9251,7 @@ test io-75.7 {
 } -match glob -result {1 {error reading "file*":\
     invalid or incomplete multibyte or wide character}}
 
-test io-75.8 {invalid utf-8 encoding eof handling (-profile strict)} -setup {
+test io-75.8 {invalid utf-8 encoding eof first handling (-profile strict)} -setup {
     set fn [makeFile {} io-75.8]
     set f [open $fn w+]
     fconfigure $f -encoding binary
@@ -9254,7 +9273,7 @@ test io-75.8 {invalid utf-8 encoding eof handling (-profile strict)} -setup {
     removeFile io-75.8
 } -result {41 1 {}}
 
-test io-75.8.eoflater {invalid utf-8 encoding eof handling (-profile strict)} -setup {
+test io-75.8.eoflater {invalid utf-8 encoding eof after handling (-profile strict)} -setup {
     set fn [makeFile {} io-75.8]
     set f [open $fn w+]
     # This also configures the channel encoding profile as strict.