diff tests/pdiff @ 28052:b59ef0c21405

tests: use portable diff script via extdiff extension

Before this patch, some tests using external "diff" command via
extdiff extension fail on Solaris, because of incompatibility of
"diff" command and its output.

For example, system standard "diff" (= /usr/bin/diff) on Solaris
differs from GNU diff in points below:

  - "-N" (treat absent files as empty) option isn't supported

  - files are examined not in dictionary order
    (maybe, in order in storage)

This patch introduces portable diff script "pdiff" and make tests use
it via extdiff extension.

For portability of tests, this patch invokes "pdiff" script with
explicit "sh", because standard shell of runtime platform ("cmd.exe"
on Windows) is used at first to invoke external diff command.

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/tests/pdiff	Mon Feb 08 18:29:17 2016 +0900
@@ -0,0 +1,58 @@
+#!/bin/sh
+
+# Script to get stable diff output on any platform.
+#
+# Output of this script is almost equivalent to GNU diff with "-Nru".
+#
+# Use this script as "hg pdiff" via extdiff extension with preparation
+# below in test scripts:
+#
+#   $ cat >> $HGRCPATH <<EOF
+#   > [extdiff]
+#   > pdiff = sh "$RUNTESTDIR/pdiff"
+#   > EOF
+
+filediff(){
+    # USAGE: filediff file1 file2 [header]
+
+    # compare with /dev/null if file doesn't exist (as "-N" option)
+    file1="$1"
+    if test ! -f "$file1"; then
+        file1=/dev/null
+    fi
+    file2="$2"
+    if test ! -f "$file2"; then
+        file2=/dev/null
+    fi
+
+    if cmp -s "$file1" "$file2"; then
+        # Return immediately, because comparison isn't needed. This
+        # also avoids redundant message of diff like "No differences
+        # encountered" (on Solaris)
+        return
+    fi
+
+    if test -n "$3"; then
+        # show header only in recursive case
+        echo "$3"
+    fi
+
+    # replace "/dev/null" by corresponded filename (as "-N" option)
+    diff -u "$file1" "$file2" |
+    sed "s@^--- /dev/null\(.*\)\$@--- $1\1@" |
+    sed "s@^\+\+\+ /dev/null\(.*\)\$@+++ $2\1@"
+}
+
+if test -d "$1" -o -d "$2"; then
+    # ensure comparison in dictionary order
+    (
+    if test -d "$1"; then (cd "$1" && find . -type f); fi
+    if test -d "$2"; then (cd "$2" && find . -type f); fi
+    ) |
+    sed 's@^\./@@g' | sort | uniq |
+    while read file; do
+        filediff "$1/$file" "$2/$file" "diff -Nru $1/$file $2/$file"
+    done
+else
+    filediff "$1" "$2"
+fi