tests/test-patch-offset

patch: better handling of sequence of offset patch hunks (issue1941)

The built-in patch implementation applied the hunks to the wrong lines of the
file if the file in the repo has been modified to skew the patch line numbers
and the file contains repetitive sequences of lines.

#!/bin/sh

cat > writepatterns.py <<EOF
import sys

path = sys.argv[1]
patterns = sys.argv[2:]

fp = file(path, 'wb')
for pattern in patterns:
    count = int(pattern[0:-1])
    char = pattern[-1] + '\n'
    fp.write(char*count)
fp.close()
EOF

echo % prepare repo
hg init a
cd a

# These initial lines of Xs were not in the original file used to generate
# the patch.  So all the patch hunks need to be applied to a constant offset
# within this file.  If the offset isn't tracked then the hunks can be
# applied to the wrong lines of this file.
python ../writepatterns.py a 34X 10A 1B 10A 1C 10A 1B 10A 1D 10A 1B 10A 1E 10A 1B 10A
hg commit -Am adda

# This is a cleaner patch generated via diff
# In this case it reproduces the problem when
# the output of hg export does not
echo % import patch
hg import -v -m 'b' -d '2 0' - <<EOF
--- a/a	2009-12-08 19:26:17.000000000 -0800
+++ b/a	2009-12-08 19:26:17.000000000 -0800
@@ -9,7 +9,7 @@
 A
 A
 B
-A
+a
 A
 A
 A
@@ -53,7 +53,7 @@
 A
 A
 B
-A
+a
 A
 A
 A
@@ -75,7 +75,7 @@
 A
 A
 B
-A
+a
 A
 A
 A
EOF

echo % compare imported changes against reference file
python ../writepatterns.py aref 34X 10A 1B 1a 9A 1C 10A 1B 10A 1D 10A 1B 1a 9A 1E 10A 1B 1a 9A
diff -u aref a