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.

5 files changed, 54 insertions, 63 deletions

diff --git a/src/amiga/map.c b/src/amiga/map.c
deleted file mode 100644
index 0ba7995c6..000000000
--- a/src/amiga/map.c
+++ /dev/null
@@ -1,48 +0,0 @@
-/*
- * Copyright (C) the libgit2 contributors. All rights reserved.
- *
- * This file is part of libgit2, distributed under the GNU GPL v2 with
- * a Linking Exception. For full terms see the included COPYING file.
- */
-#include <git2/common.h>
-
-#ifndef GIT_WIN32
-
-#include "posix.h"
-#include "map.h"
-#include <errno.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
-
diff --git a/src/indexer.c b/src/indexer.c
index 88897d07d..718c69814 100644
--- a/src/indexer.c
+++ b/src/indexer.c
@@ -441,8 +441,8 @@ int git_indexer_append(git_indexer *idx, const void *data, size_t size, git_tran
 
 	processed = stats->indexed_objects;
 
-	if (git_filebuf_write(&idx->pack_file, data, size) < 0)
-		return -1;
+	if ((error = git_filebuf_write(&idx->pack_file, data, size)) < 0)
+		return error;
 
 	hash_partially(idx, data, (int)size);
 
@@ -450,12 +450,12 @@ int git_indexer_append(git_indexer *idx, const void *data, size_t size, git_tran
 	if (idx->opened_pack) {
 		idx->pack->mwf.size += size;
 	} else {
-		if (open_pack(&idx->pack, idx->pack_file.path_lock) < 0)
-			return -1;
+		if ((error = open_pack(&idx->pack, idx->pack_file.path_lock)) < 0)
+			return error;
 		idx->opened_pack = 1;
 		mwf = &idx->pack->mwf;
-		if (git_mwindow_file_register(&idx->pack->mwf) < 0)
-			return -1;
+		if ((error = git_mwindow_file_register(&idx->pack->mwf)) < 0)
+			return error;
 	}
 
 	if (!idx->parsed_header) {
@@ -464,8 +464,8 @@ int git_indexer_append(git_indexer *idx, const void *data, size_t size, git_tran
 		if ((unsigned)idx->pack->mwf.size < sizeof(struct git_pack_header))
 			return 0;
 
-		if (parse_header(&idx->hdr, idx->pack) < 0)
-			return -1;
+		if ((error = parse_header(&idx->hdr, idx->pack)) < 0)
+			return error;
 
 		idx->parsed_header = 1;
 		idx->nr_objects = ntohl(hdr->hdr_entries);
@@ -503,6 +503,7 @@ int git_indexer_append(git_indexer *idx, const void *data, size_t size, git_tran
 
 	/* As the file grows any windows we try to use will be out of date */
 	git_mwindow_free_all(mwf);
+
 	while (processed < idx->nr_objects) {
 		git_packfile_stream *stream = &idx->stream;
 		git_off_t entry_start = idx->off;
@@ -520,7 +521,7 @@ int git_indexer_append(git_indexer *idx, const void *data, size_t size, git_tran
 				return 0;
 			}
 			if (error < 0)
-				return error;
+				goto on_error;
 
 			git_mwindow_close(&w);
 			idx->entry_start = entry_start;
@@ -533,7 +534,7 @@ int git_indexer_append(git_indexer *idx, const void *data, size_t size, git_tran
 					return 0;
 				}
 				if (error < 0)
-					return error;
+					goto on_error;
 
 				idx->have_delta = 1;
 			} else {
@@ -542,9 +543,10 @@ int git_indexer_append(git_indexer *idx, const void *data, size_t size, git_tran
 			}
 
 			idx->have_stream = 1;
-			if (git_packfile_stream_open(stream, idx->pack, idx->off) < 0)
-				goto on_error;
 
+			error = git_packfile_stream_open(stream, idx->pack, idx->off);
+			if (error < 0)
+				goto on_error;
 		}
 
 		if (idx->have_delta) {
@@ -858,7 +860,7 @@ int git_indexer_commit(git_indexer *idx, git_transfer_progress *stats)
 
 	/* Test for this before resolve_deltas(), as it plays with idx->off */
 	if (idx->off < idx->pack->mwf.size - 20) {
-		giterr_set(GITERR_INDEXER, "unexpected data at the end of the pack");
+		giterr_set(GITERR_INDEXER, "Unexpected data at the end of the pack");
 		return -1;
 	}
 
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
diff --git a/src/unix/map.c b/src/unix/map.c
index 7de99c99d..e62ab3e76 100644
--- a/src/unix/map.c
+++ b/src/unix/map.c
@@ -6,7 +6,7 @@
  */
 #include <git2/common.h>
 
-#ifndef GIT_WIN32
+#if !defined(GIT_WIN32) && !defined(NO_MMAP)
 
 #include "map.h"
 #include <sys/mman.h>
diff --git a/src/win32/map.c b/src/win32/map.c
index 44c6c4e2e..902ea3994 100644
--- a/src/win32/map.c
+++ b/src/win32/map.c
@@ -8,6 +8,7 @@
 #include "map.h"
 #include <errno.h>
 
+#ifndef NO_MMAP
 
 static DWORD get_page_size(void)
 {
@@ -112,4 +113,4 @@ int p_munmap(git_map *map)
 	return error;
 }
 
-
+#endif