commit-graph: normalize commit-graph filenames

When writing commit-graph files, we append path data to an
object directory, which may be specified by the user via the
'--object-dir' option. If the user supplies a trailing slash,
or some other alternative path format, the resulting path may
be usable for writing to the correct location. However, when
expiring graph files from the <obj-dir>/info/commit-graphs
directory during a write, we need to compare paths with exact
string matches.

Normalize the commit-graph filenames to avoid ambiguity. This
creates extra allocations, but this is a constant multiple of
the number of commit-graph files, which should be a number in
the single digits.

Further normalize the object directory in the context. Due to
a comparison between g->obj_dir and ctx->obj_dir in
split_graph_merge_strategy(), a trailing slash would prevent
any merging of layers within the same object directory. The
check is there to ensure we do not merge across alternates.
Update the tests to include a case with this trailing slash
problem.

Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/commit-graph.c b/commit-graph.c
index 3599ae664d70eaf666a8df9fc79fcd140f8771e5..c91e6f0fb821582706b3c9ee232da1335ea7427d 100644 (file)
--- a/commit-graph.c
+++ b/commit-graph.c
@@ -43,15 +43,23 @@
 
 char *get_commit_graph_filename(const char *obj_dir)
 {
-       return xstrfmt("%s/info/commit-graph", obj_dir);
+       char *filename = xstrfmt("%s/info/commit-graph", obj_dir);
+       char *normalized = xmalloc(strlen(filename) + 1);
+       normalize_path_copy(normalized, filename);
+       free(filename);
+       return normalized;
 }
 
 static char *get_split_graph_filename(const char *obj_dir,
                                      const char *oid_hex)
 {
-       return xstrfmt("%s/info/commit-graphs/graph-%s.graph",
-                      obj_dir,
-                      oid_hex);
+       char *filename = xstrfmt("%s/info/commit-graphs/graph-%s.graph",
+                                obj_dir,
+                                oid_hex);
+       char *normalized = xmalloc(strlen(filename) + 1);
+       normalize_path_copy(normalized, filename);
+       free(filename);
+       return normalized;
 }
 
 static char *get_chain_filename(const char *obj_dir)
@@ -746,7 +754,7 @@ struct packed_oid_list {
 
 struct write_commit_graph_context {
        struct repository *r;
-       const char *obj_dir;
+       char *obj_dir;
        char *graph_name;
        struct packed_oid_list oids;
        struct packed_commit_list commits;
@@ -1729,7 +1737,6 @@ static void expire_commit_graphs(struct write_commit_graph_context *ctx)
 
                if (!found)
                        unlink(path.buf);
-
        }
 }
 
@@ -1741,6 +1748,7 @@ int write_commit_graph(const char *obj_dir,
 {
        struct write_commit_graph_context *ctx;
        uint32_t i, count_distinct = 0;
+       size_t len;
        int res = 0;
 
        if (!commit_graph_compatible(the_repository))
@@ -1748,7 +1756,14 @@ int write_commit_graph(const char *obj_dir,
 
        ctx = xcalloc(1, sizeof(struct write_commit_graph_context));
        ctx->r = the_repository;
-       ctx->obj_dir = obj_dir;
+
+       /* normalize object dir with no trailing slash */
+       ctx->obj_dir = xmallocz(strlen(obj_dir) + 1);
+       normalize_path_copy(ctx->obj_dir, obj_dir);
+       len = strlen(ctx->obj_dir);
+       if (len && ctx->obj_dir[len - 1] == '/')
+               ctx->obj_dir[len - 1] = 0;
+
        ctx->append = flags & COMMIT_GRAPH_APPEND ? 1 : 0;
        ctx->report_progress = flags & COMMIT_GRAPH_PROGRESS ? 1 : 0;
        ctx->split = flags & COMMIT_GRAPH_SPLIT ? 1 : 0;
@@ -1856,6 +1871,7 @@ int write_commit_graph(const char *obj_dir,
        free(ctx->graph_name);
        free(ctx->commits.list);
        free(ctx->oids.list);
+       free(ctx->obj_dir);
 
        if (ctx->commit_graph_filenames_after) {
                for (i = 0; i < ctx->num_commit_graphs_after; i++) {

diff --git a/t/t5324-split-commit-graph.sh b/t/t5324-split-commit-graph.sh
index 130f2baf44d7a305a2c0e78ff80b9c0d140a7e74..fc0d00751c301ba979817312efb3a89089e8da39 100755 (executable)
--- a/t/t5324-split-commit-graph.sh
+++ b/t/t5324-split-commit-graph.sh
@@ -163,7 +163,12 @@ test_expect_success 'create fork and chain across alternate' '
                test_line_count = 1 graph-files &&
                git -c core.commitGraph=true  rev-list HEAD >expect &&
                git -c core.commitGraph=false rev-list HEAD >actual &&
-               test_cmp expect actual
+               test_cmp expect actual &&
+               test_commit 14 &&
+               git commit-graph write --reachable --split --object-dir=.git/objects/ &&
+               test_line_count = 3 $graphdir/commit-graph-chain &&
+               ls $graphdir/graph-*.graph >graph-files &&
+               test_line_count = 1 graph-files
        )
 '