Merge branch 'jc/read-tree-safety' into next

[git.git] / read-tree.c

diff --git a/read-tree.c b/read-tree.c
index 675a59f..a3ada55 100644 (file)
--- a/read-tree.c
+++ b/read-tree.c
@@ -411,7 +411,7 @@ static void verify_uptodate(struct cache_entry *ce)
 {
        struct stat st;
 
-       if (index_only)
+       if (index_only || reset)
                return;
 
        if (!lstat(ce->name, &st)) {
@@ -435,6 +435,21 @@ static void invalidate_ce_path(struct cache_entry *ce)
                cache_tree_invalidate_path(active_cache_tree, ce->name);
 }
 
+/*
+ * We do not want to remove or overwrite a working tree file that
+ * is not tracked.
+ */
+static void verify_absent(const char *path, const char *action)
+{
+       struct stat st;
+
+       if (index_only || reset || !update)
+               return;
+       if (!lstat(path, &st))
+               die("Untracked working tree file '%s' "
+                   "would be %s by merge.", path, action);
+}
+
 static int merged_entry(struct cache_entry *merge, struct cache_entry *old)
 {
        merge->ce_flags |= htons(CE_UPDATE);
@@ -453,8 +468,11 @@ static int merged_entry(struct cache_entry *merge, struct cache_entry *old)
                        invalidate_ce_path(old);
                }
        }
-       else
+       else {
+               verify_absent(merge->name, "overwritten");
                invalidate_ce_path(merge);
+       }
+
        merge->ce_flags &= ~htons(CE_STAGEMASK);
        add_cache_entry(merge, ADD_CACHE_OK_TO_ADD);
        return 1;
@@ -464,6 +482,8 @@ static int deleted_entry(struct cache_entry *ce, struct cache_entry *old)
 {
        if (old)
                verify_uptodate(old);
+       else
+               verify_absent(ce->name, "removed");
        ce->ce_mode = 0;
        add_cache_entry(ce, ADD_CACHE_OK_TO_ADD);
        invalidate_ce_path(ce);
@@ -500,6 +520,7 @@ static int threeway_merge(struct cache_entry **stages)
        int count;
        int head_match = 0;
        int remote_match = 0;
+       const char *path = NULL;
 
        int df_conflict_head = 0;
        int df_conflict_remote = 0;
@@ -511,8 +532,11 @@ static int threeway_merge(struct cache_entry **stages)
        for (i = 1; i < head_idx; i++) {
                if (!stages[i])
                        any_anc_missing = 1;
-               else
+               else {
+                       if (!path)
+                               path = stages[i]->name;
                        no_anc_exists = 0;
+               }
        }
 
        index = stages[0];
@@ -528,8 +552,15 @@ static int threeway_merge(struct cache_entry **stages)
                remote = NULL;
        }
 
+       if (!path && index)
+               path = index->name;
+       if (!path && head)
+               path = head->name;
+       if (!path && remote)
+               path = remote->name;
+
        /* First, if there's a #16 situation, note that to prevent #13
-        * and #14. 
+        * and #14.
         */
        if (!same(remote, head)) {
                for (i = 1; i < head_idx; i++) {
@@ -588,6 +619,8 @@ static int threeway_merge(struct cache_entry **stages)
                    (remote_deleted && head && head_match)) {
                        if (index)
                                return deleted_entry(index, index);
+                       else if (path)
+                               verify_absent(path, "removed");
                        return 0;
                }
                /*
@@ -605,6 +638,8 @@ static int threeway_merge(struct cache_entry **stages)
        if (index) {
                verify_uptodate(index);
        }
+       else if (path)
+               verify_absent(path, "overwritten");
 
        nontrivial_merge = 1;
 
@@ -725,7 +760,7 @@ static int oneway_merge(struct cache_entry **src)
 
        if (!a) {
                invalidate_ce_path(old);
-               return deleted_entry(old, NULL);
+               return deleted_entry(old, old);
        }
        if (old && same(old, a)) {
                if (reset) {
@@ -736,7 +771,7 @@ static int oneway_merge(struct cache_entry **src)
                }
                return keep_entry(old);
        }
-       return merged_entry(a, NULL);
+       return merged_entry(a, old);
 }
 
 static int read_cache_unmerged(void)