For iOS Chinese IMEs, punctuation (including space-triggered conversion) is produced via non-composition paths and is not reliably available at keydown time. Keydown-only handling can miss these inputs; keyup/input stage is where the final character is reliably observable.
[09:08:04.163] #151 keydown len=0 sel=[0,0,none] textArea="" key=" " code="Space" keyCode=229 which=229 isComposing=false
[09:08:04.170] #152 beforeinput len=0 sel=[0,0,none] textArea="" inputType="insertText" data=" " isComposing=false composed=true
[09:08:04.173] #153 input len=1 sel=[1,1,none] textArea=" " inputType="insertText" data=" " isComposing=false composed=true
[09:08:04.174] #154 selectionchange(document) len=1 sel=[1,1,none] textArea=" "
[09:08:04.175] #155 keyup len=1 sel=[1,1,none] textArea=" " key=" " code="Space" keyCode=32 which=32 isComposing=false
[09:08:06.806] #156 keydown len=1 sel=[1,1,none] textArea=" " key="，" code="Unidentified" keyCode=229 which=229 isComposing=false
[09:08:06.816] #157 beforeinput len=1 sel=[1,1,none] textArea=" " inputType="insertText" data="，" isComposing=false composed=true
[09:08:06.818] #158 input len=2 sel=[2,2,none] textArea=" ，" inputType="insertText" data="，" isComposing=false composed=true
[09:08:06.820] #159 keyup len=2 sel=[2,2,none] textArea=" ，" key="，" code="Unidentified" keyCode=0 which=0 isComposing=false
[09:08:06.820] #160 selectionchange(document) len=2 sel=[2,2,none] textArea=" ，"
[09:08:09.552] #161 keydown len=2 sel=[2,2,none] textArea=" ，" key="！" code="Unidentified" keyCode=229 which=229 isComposing=false
[09:08:09.561] #162 beforeinput len=2 sel=[2,2,none] textArea=" ，" inputType="insertText" data="！" isComposing=false composed=true
[09:08:09.563] #163 input len=3 sel=[3,3,none] textArea=" ，！" inputType="insertText" data="！" isComposing=false composed=true
[09:08:09.566] #164 selectionchange(document) len=3 sel=[3,3,none] textArea=" ，！"
[09:08:09.569] #165 keyup len=3 sel=[3,3,none] textArea=" ，！" key="！" code="Unidentified" keyCode=0 which=0 isComposing=false
[09:08:11.266] #166 keydown len=3 sel=[3,3,none] textArea=" ，！" key=" " code="Space" keyCode=229 which=229 isComposing=false
[09:08:11.275] #167 beforeinput len=3 sel=[3,3,none] textArea=" ，！" inputType="insertText" data=" " isComposing=false composed=true
[09:08:11.281] #168 input len=4 sel=[4,4,none] textArea=" ，！ " inputType="insertText" data=" " isComposing=false composed=true
[09:08:11.287] #169 keyup len=4 sel=[4,4,none] textArea=" ，！ " key=" " code="Space" keyCode=32 which=32 isComposing=false
[09:08:11.293] #170 selectionchange(document) len=4 sel=[4,4,none] textArea=" ，！ "
[09:08:11.866] #171 keydown len=4 sel=[4,4,none] textArea=" ，！ " key=" " code="Space" keyCode=229 which=229 isComposing=false
[09:08:11.877] #172 beforeinput len=4 sel=[4,4,none] textArea=" ，！ " inputType="deleteContentBackward" data="" isComposing=false composed=true
[09:08:11.884] #173 input len=3 sel=[3,3,none] textArea=" ，！" inputType="deleteContentBackward" data="" isComposing=false composed=true
[09:08:11.890] #174 beforeinput len=3 sel=[3,3,none] textArea=" ，！" inputType="insertText" data="。" isComposing=false composed=true
[09:08:11.896] #175 input len=4 sel=[4,4,none] textArea=" ，！。" inputType="insertText" data="。" isComposing=false composed=true
[09:08:11.900] #176 keyup len=4 sel=[4,4,none] textArea=" ，！。" key=" " code="Space" keyCode=32 which=32 isComposing=false
Details
Steps to reproduce
，,！).Expected result: punctuation/space should be sent to the terminal as normal input.
Actual behavior: punctuation/space is often not sent to the terminal (dropped), even though corresponding
beforeinput/input/keyupevents occur on iOS.Special case
When pressing
Spacetwice consecutively, iOS IME may transform it into。via a delete-then-insert sequence:beforeinput/inputwithdeleteContentBackwardbeforeinput/inputwithinsertTextdata=。Additionally, this sequence can hit the last branch of
_handleAnyTextareaChanges(same length but different value), which sends the wholenewValue(entire textarea content) instead of a minimal diff. That may cause duplicated or over-sent data.Root cause
For iOS Chinese IMEs, punctuation (including space-triggered conversion) is produced via non-composition paths and is not reliably available at
keydowntime. Keydown-only handling can miss these inputs; keyup/input stage is where the final character is reliably observable.Raw event sequence