procutil: make stream detection in make_line_buffered more correct and strict
In make_line_buffered(), we don’t want to wrap the stream if we know that lines
get flushed to the underlying raw stream already.
Previously, the heuristic was too optimistic. It assumed that any stream which
is not an instance of io.BufferedIOBase doesn’t need wrapping. However, there
are buffered streams that aren’t instances of io.BufferedIOBase, like
Mercurial’s own winstdout.
The new logic is different in two ways:
First, only for the check, if unwraps any combination of WriteAllWrapper and
winstdout.
Second, it skips wrapping the stream only if it is an instance of io.RawIOBase
(or already wrapped). If it is an instance of io.BufferedIOBase, it gets
wrapped. In any other case, the function raises an exception. This ensures
that, if an unknown stream is passed or we add another wrapper in the future,
we don’t wrap the stream if it’s already line buffered or not wrap the stream
if it’s not line buffered. In fact, this was already helpful during development
of this change. Without it, I possibly would have forgot that WriteAllWrapper
needs to be ignored for the check, leading to unnecessary wrapping if stdout is
unbuffered.
The alternative would have been to always wrap unknown streams. However, I
don’t think that anyone would benefit from being less strict. We can expect
streams from the standard library to be subclassing either io.RawIOBase or
io.BufferedIOBase, so running Mercurial in the standard way should not regress
by this change. Py2exe might replace sys.stdout and sys.stderr, but that
currently breaks Mercurial anyway and also these streams don’t claim to be
interactive, so this function is not called for them.
$ hg init a
$ cd a
$ cp "$TESTDIR/binfile.bin" .
$ hg add binfile.bin
$ hg ci -m 'add binfile.bin'
$ echo >> binfile.bin
$ hg ci -m 'change binfile.bin'
$ hg revert -r 0 binfile.bin
$ hg ci -m 'revert binfile.bin'
$ hg cp binfile.bin nonbinfile
$ echo text > nonbinfile
$ hg ci -m 'make non-binary copy of binary file'
$ hg diff --nodates -r 0 -r 1
diff -r 48b371597640 -r acea2ab458c8 binfile.bin
Binary file binfile.bin has changed
$ hg diff --nodates -r 0 -r 2
$ hg diff --git -r 0 -r 1
diff --git a/binfile.bin b/binfile.bin
index 37ba3d1c6f17137d9c5f5776fa040caf5fe73ff9..58dc31a9e2f40f74ff3b45903f7d620b8e5b7356
GIT binary patch
literal 594
zc$@)J0<HatP)<h;3K|Lk000e1NJLTq000mG000mO0ssI2kdbIM00009a7bBm000XU
z000XU0RWnu7ytkO2XskIMF-Uh9TW;VpMjwv0005-Nkl<ZD9@FWPs=e;7{<>W$NUkd
zX$nnYLt$-$V!?uy+1V%`z&Eh=ah|duER<4|QWhju3gb^nF*8iYobxWG-qqXl=2~5M
z*IoDB)sG^CfNuoBmqLTVU^<;@nwHP!1wrWd`{(mHo6VNXWtyh{alzqmsH*yYzpvLT
zLdY<T=ks|woh-`&01!ej#(xbV1f|pI*=%;d-%F*E*X#ZH`4I%6SS+$EJDE&ct=8po
ziN#{?_j|kD%Cd|oiqds`xm@;oJ-^?NG3Gdqrs?5u*zI;{nogxsx~^|Fn^Y?Gdc6<;
zfMJ+iF1J`LMx&A2?dEwNW8ClebzPTbIh{@$hS6*`kH@1d%Lo7fA#}N1)oN7`gm$~V
z+wDx#)OFqMcE{s!JN0-xhG8ItAjVkJwEcb`3WWlJfU2r?;Pd%dmR+q@mSri5q9_W-
zaR2~ECX?B2w+zELozC0s*6Z~|QG^f{3I#<`?)Q7U-JZ|q5W;9Q8i_=pBuSzunx=U;
z9C)5jBoYw9^?EHyQl(M}1OlQcCX>lXB*ODN003Z&P17_@)3Pi=i0wb04<W?v-u}7K
zXmmQA+wDgE!qR9o8jr`%=ab_&uh(l?R=r;Tjiqon91I2-hIu?57~@*4h7h9uORK#=
gQItJW-{SoTm)8|5##k|m00000NkvXXu0mjf3JwksH2?qr
$ hg diff --git -r 0 -r 2
$ hg diff --config diff.nobinary=True --git -r 0 -r 1
diff --git a/binfile.bin b/binfile.bin
Binary file binfile.bin has changed
$ HGPLAIN=1 hg diff --config diff.nobinary=True --git -r 0 -r 1
diff --git a/binfile.bin b/binfile.bin
index 37ba3d1c6f17137d9c5f5776fa040caf5fe73ff9..58dc31a9e2f40f74ff3b45903f7d620b8e5b7356
GIT binary patch
literal 594
zc$@)J0<HatP)<h;3K|Lk000e1NJLTq000mG000mO0ssI2kdbIM00009a7bBm000XU
z000XU0RWnu7ytkO2XskIMF-Uh9TW;VpMjwv0005-Nkl<ZD9@FWPs=e;7{<>W$NUkd
zX$nnYLt$-$V!?uy+1V%`z&Eh=ah|duER<4|QWhju3gb^nF*8iYobxWG-qqXl=2~5M
z*IoDB)sG^CfNuoBmqLTVU^<;@nwHP!1wrWd`{(mHo6VNXWtyh{alzqmsH*yYzpvLT
zLdY<T=ks|woh-`&01!ej#(xbV1f|pI*=%;d-%F*E*X#ZH`4I%6SS+$EJDE&ct=8po
ziN#{?_j|kD%Cd|oiqds`xm@;oJ-^?NG3Gdqrs?5u*zI;{nogxsx~^|Fn^Y?Gdc6<;
zfMJ+iF1J`LMx&A2?dEwNW8ClebzPTbIh{@$hS6*`kH@1d%Lo7fA#}N1)oN7`gm$~V
z+wDx#)OFqMcE{s!JN0-xhG8ItAjVkJwEcb`3WWlJfU2r?;Pd%dmR+q@mSri5q9_W-
zaR2~ECX?B2w+zELozC0s*6Z~|QG^f{3I#<`?)Q7U-JZ|q5W;9Q8i_=pBuSzunx=U;
z9C)5jBoYw9^?EHyQl(M}1OlQcCX>lXB*ODN003Z&P17_@)3Pi=i0wb04<W?v-u}7K
zXmmQA+wDgE!qR9o8jr`%=ab_&uh(l?R=r;Tjiqon91I2-hIu?57~@*4h7h9uORK#=
gQItJW-{SoTm)8|5##k|m00000NkvXXu0mjf3JwksH2?qr
$ hg diff --git -r 2 -r 3
diff --git a/binfile.bin b/nonbinfile
copy from binfile.bin
copy to nonbinfile
index 37ba3d1c6f17137d9c5f5776fa040caf5fe73ff9..8e27be7d6154a1f68ea9160ef0e18691d20560dc
GIT binary patch
literal 5
Mc$_OqttjCF00uV!&;S4c
$ cd ..
Test text mode with extended git-style diff format
$ hg init b
$ cd b
$ cat > writebin.py <<EOF
> import sys
> path = sys.argv[1]
> open(path, 'wb').write(b'\x00\x01\x02\x03')
> EOF
$ "$PYTHON" writebin.py binfile.bin
$ hg add binfile.bin
$ hg ci -m 'add binfile.bin'
$ echo >> binfile.bin
$ hg ci -m 'change binfile.bin'
$ hg diff --git -a -r 0 -r 1
diff --git a/binfile.bin b/binfile.bin
--- a/binfile.bin
+++ b/binfile.bin
@@ -1,1 +1,1 @@
-\x00\x01\x02\x03 (esc)
\ No newline at end of file
+\x00\x01\x02\x03 (esc)
$ HGPLAIN=1 hg diff --git -a -r 0 -r 1
diff --git a/binfile.bin b/binfile.bin
--- a/binfile.bin
+++ b/binfile.bin
@@ -1,1 +1,1 @@
-\x00\x01\x02\x03 (esc)
\ No newline at end of file
+\x00\x01\x02\x03 (esc)
Test binary mode with extended git-style diff format
$ hg diff --no-binary -r 0 -r 1
diff -r fb45f71337ad -r 9ca112d1a3c1 binfile.bin
Binary file binfile.bin has changed
$ hg diff --git --no-binary -r 0 -r 1
diff --git a/binfile.bin b/binfile.bin
Binary file binfile.bin has changed
$ hg diff --git --binary -r 0 -r 1
diff --git a/binfile.bin b/binfile.bin
index eaf36c1daccfdf325514461cd1a2ffbc139b5464..ba71a782e93f3fb63a428383706065e3ec2828e9
GIT binary patch
literal 5
Mc${NkWMbw50018V5dZ)H
$ hg diff --git --binary --config diff.nobinary=True -r 0 -r 1
diff --git a/binfile.bin b/binfile.bin
index eaf36c1daccfdf325514461cd1a2ffbc139b5464..ba71a782e93f3fb63a428383706065e3ec2828e9
GIT binary patch
literal 5
Mc${NkWMbw50018V5dZ)H
$ hg diff --git --binary --text -r 0 -r 1
diff --git a/binfile.bin b/binfile.bin
--- a/binfile.bin
+++ b/binfile.bin
@@ -1,1 +1,1 @@
-\x00\x01\x02\x03 (esc)
\ No newline at end of file
+\x00\x01\x02\x03 (esc)
$ cd ..