Test cancel from indexer progress callback

This adds tests that try canceling an indexer operation from
within the progress callback.

After writing the tests, I wanted to run this under valgrind and
had a number of errors in that situation because mmap wasn't
working.  I added a CMake option to force emulation of mmap and
consolidated the Amiga-specific code into that new place (so we
don't actually need separate Amiga code now, just have to turn on
-DNO_MMAP).

Additionally, I made the indexer code propagate error codes more
reliably than it used to.

1 files changed, 36 insertions, 0 deletions

diff --git a/src/posix.c b/src/posix.c
index b75109b83..525785f35 100644
--- a/src/posix.c
+++ b/src/posix.c
@@ -203,4 +203,40 @@ int p_write(git_file fd, const void *buf, size_t cnt)
 	return 0;
 }
 
+#ifdef NO_MMAP
 
+#include "map.h"
+
+int p_mmap(git_map *out, size_t len, int prot, int flags, int fd, git_off_t offset)
+{
+	GIT_MMAP_VALIDATE(out, len, prot, flags);
+
+	out->data = NULL;
+	out->len = 0;
+
+	if ((prot & GIT_PROT_WRITE) && ((flags & GIT_MAP_TYPE) == GIT_MAP_SHARED)) {
+		giterr_set(GITERR_OS, "Trying to map shared-writeable");
+		return -1;
+	}
+
+	out->data = malloc(len);
+	GITERR_CHECK_ALLOC(out->data);
+
+	if ((p_lseek(fd, offset, SEEK_SET) < 0) || ((size_t)p_read(fd, out->data, len) != len)) {
+		giterr_set(GITERR_OS, "mmap emulation failed");
+		return -1;
+	}
+
+	out->len = len;
+	return 0;
+}
+
+int p_munmap(git_map *map)
+{
+	assert(map != NULL);
+	free(map->data);
+
+	return 0;
+}
+
+#endif