Pylauncher does not correctly detect a BOM when searching for the shebang

[chris-eibl]

Bug report

Bug description:

This is due to

cpython/PC/launcher2.c

Lines 1080 to 1081 in 475f933

	if (bytesRead > 3 && *b == 0xEF) {
	if (*++b == 0xBB && *++b == 0xBF) {

for wich clang-cl creates the following warnings:

1>..\PC\launcher2.c(1080,29): warning : result of comparison of constant 239 with expression of type 'char' is always false [-Wtautological-constant-out-of-range-compare]
1>..\PC\launcher2.c(1081,34): warning : result of comparison of constant 191 with expression of type 'char' is always false [-Wtautological-constant-out-of-range-compare]
1>..\PC\launcher2.c(1081,18): warning : result of comparison of constant 187 with expression of type 'char' is always false [-Wtautological-constant-out-of-range-compare]

CPython versions tested on:

CPython main branch

Operating systems tested on:

Windows

Linked PRs

• gh-131020: Pylauncher does not correctly detect a BOM when searching for the shebang #131021
• [3.13] gh-131020: py.exe launcher does not correctly detect a BOM when searching for the shebang (GH-131021) #131047
• [3.12] gh-131020: py.exe launcher does not correctly detect a BOM when searching for the shebang (GH-131021) #131048

[picnixz]

Reopening as it appeared that this wasn't true duplicate although the errors were similar.

[picnixz]

Closing since it was completed. Thanks for the report and fix!