t4051: rewrite, add more tests

Remove the tests that checked against a fixed result and replace them
with more focused checks of desired properties of the created diffs.
That way we get more detailed and meaningful diagnostics.

Store test file contents in files in a subdirectory in order to avoid
cluttering the test script with them.

Use tagged commits to store the changes to test diff -W against instead
of using changes to the worktree.  Use the worktree instead to try and
apply the generated patch in order to validate it.

Document unwanted features: trailing empty lines, too much context for
appended functions, insufficient context at the end with -U0.

Helped-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Rene Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

5 files changed, 98 insertions, 0 deletions

diff --git a/t/t4051/appended1.c b/t/t4051/appended1.c
new file mode 100644
index 0000000000..a9f56f11db
--- /dev/null
+++ b/t/t4051/appended1.c
@@ -0,0 +1,15 @@
+
+int appended(void) // Begin of first part
+{
+	int i;
+	char *s = "a string";
+
+	printf("%s\n", s);
+
+	for (i = 99;
+	     i >= 0;
+	     i--) {
+		printf("%d bottles of beer on the wall\n", i);
+	}
+
+	printf("End of first part\n");
diff --git a/t/t4051/appended2.c b/t/t4051/appended2.c
new file mode 100644
index 0000000000..e651f7147b
--- /dev/null
+++ b/t/t4051/appended2.c
@@ -0,0 +1,35 @@
+	printf("Begin of second part\n");
+
+	/*
+	 * Lorem ipsum dolor sit amet, consectetuer sadipscing elitr,
+	 * sed diam nonumy eirmod tempor invidunt ut labore et dolore
+	 * magna aliquyam erat, sed diam voluptua. At vero eos et
+	 * accusam et justo duo dolores et ea rebum. Stet clita kasd
+	 * gubergren, no sea takimata sanctus est Lorem ipsum dolor
+	 * sit amet.
+	 *
+	 * Lorem ipsum dolor sit amet, consectetuer sadipscing elitr,
+	 * sed diam nonumy eirmod tempor invidunt ut labore et dolore
+	 * magna aliquyam erat, sed diam voluptua. At vero eos et
+	 * accusam et justo duo dolores et ea rebum. Stet clita kasd
+	 * gubergren, no sea takimata sanctus est Lorem ipsum dolor
+	 * sit amet.
+	 *
+	 * Lorem ipsum dolor sit amet, consectetuer sadipscing elitr,
+	 * sed diam nonumy eirmod tempor invidunt ut labore et dolore
+	 * magna aliquyam erat, sed diam voluptua. At vero eos et
+	 * accusam et justo duo dolores et ea rebum. Stet clita kasd
+	 * gubergren, no sea takimata sanctus est Lorem ipsum dolor
+	 * sit amet.
+	 *
+	 * Lorem ipsum dolor sit amet, consectetuer sadipscing elitr,
+	 * sed diam nonumy eirmod tempor invidunt ut labore et dolore
+	 * magna aliquyam erat, sed diam voluptua. At vero eos et
+	 * accusam et justo duo dolores et ea rebum. Stet clita kasd
+	 * gubergren, no sea takimata sanctus est Lorem ipsum dolor
+	 * sit amet.
+	 *
+	 */
+
+	return 0;
+}	// End of second part
diff --git a/t/t4051/dummy.c b/t/t4051/dummy.c
new file mode 100644
index 0000000000..a43016e870
--- /dev/null
+++ b/t/t4051/dummy.c
@@ -0,0 +1,7 @@
+
+static int dummy(void)	// Begin of dummy
+{
+	int rc = 0;
+
+	return rc;
+}	// End of dummy
diff --git a/t/t4051/hello.c b/t/t4051/hello.c
new file mode 100644
index 0000000000..63b1a1e4ef
--- /dev/null
+++ b/t/t4051/hello.c
@@ -0,0 +1,21 @@
+
+static void hello(void)	// Begin of hello
+{
+	/*
+	 * Classic.
+	 */
+	putchar('H');
+	putchar('e');
+	putchar('l');
+	putchar('l');
+	putchar('o');
+	putchar(' ');
+	/* delete me from hello */
+	putchar('w');
+	putchar('o');
+	putchar('r');
+	putchar('l');
+	putchar('d');
+	putchar('.');
+	putchar('\n');
+}	// End of hello
diff --git a/t/t4051/includes.c b/t/t4051/includes.c
new file mode 100644
index 0000000000..efc68f8bf6
--- /dev/null
+++ b/t/t4051/includes.c
@@ -0,0 +1,20 @@
+#include <Begin.h>
+#include <unistd.h>
+#include <stdio.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <stddef.h>
+#include <stdlib.h>
+#include <stdarg.h>
+/* delete me from includes */
+#include <string.h>
+#include <sys/types.h>
+#include <dirent.h>
+#include <sys/time.h>
+#include <time.h>
+#include <signal.h>
+#include <assert.h>
+#include <regex.h>
+#include <utime.h>
+#include <syslog.h>
+#include <End.h>