bpo-38673: dont switch to ps2 if the line starts with comment or whitespace (GH-17421)
https://bugs.python.org/issue38673
(cherry picked from commit 109fc2792a490ee5cd8a423e17d415fbdedec5c8)
Co-authored-by: Batuhan Taşkaya <47358913+isidentical@users.noreply.github.com>
diff --git a/Misc/NEWS.d/next/Core and Builtins/2019-12-01-00-17-44.bpo-38673.K_Tze-.rst b/Misc/NEWS.d/next/Core and Builtins/2019-12-01-00-17-44.bpo-38673.K_Tze-.rst
new file mode 100644
index 0000000..8f8cf88
--- /dev/null
+++ b/Misc/NEWS.d/next/Core and Builtins/2019-12-01-00-17-44.bpo-38673.K_Tze-.rst
@@ -0,0 +1 @@
+In REPL mode, don't switch to PS2 if the line starts with comment or whitespace. Based on work by Batuhan Taşkaya.
diff --git a/Parser/tokenizer.c b/Parser/tokenizer.c
index 5763e47..f84093d 100644
--- a/Parser/tokenizer.c
+++ b/Parser/tokenizer.c
@@ -1148,6 +1148,12 @@
if (col == 0 && c == '\n' && tok->prompt != NULL) {
blankline = 0; /* Let it through */
}
+ else if (tok->prompt != NULL && tok->lineno == 1) {
+ /* In interactive mode, if the first line contains
+ only spaces and/or a comment, let it through. */
+ blankline = 0;
+ col = altcol = 0;
+ }
else {
blankline = 1; /* Ignore completely */
}