Library function to check for unmerged index entries

It's small, but it was in three places already, so it should be in the
library.
Signed-off-by: NDaniel Barkalow <barkalow@iabervon.org>

builtin-merge-recursive.c

@@ -223,22 +223,11 @@ static int git_merge_trees(int index_only,
 	return rc;
 }
 
-static int unmerged_index(void)
-{
-	int i;
-	for (i = 0; i < active_nr; i++) {
-		struct cache_entry *ce = active_cache[i];
-		if (ce_stage(ce))
-			return 1;
-	}
-	return 0;
-}
-
 struct tree *write_tree_from_memory(void)
 {
 	struct tree *result = NULL;
 
-	if (unmerged_index()) {
+	if (unmerged_cache()) {
 		int i;
 		output(0, "There are unmerged index entries:");
 		for (i = 0; i < active_nr; i++) {
@@ -1524,7 +1513,7 @@ int merge_trees(struct tree *head,
 		    sha1_to_hex(head->object.sha1),
 		    sha1_to_hex(merge->object.sha1));
 
-	if (unmerged_index()) {
+	if (unmerged_cache()) {
 		struct path_list *entries, *re_head, *re_merge;
 		int i;
 		path_list_clear(&current_file_set, 1);

builtin-reset.c

@@ -44,18 +44,6 @@ static inline int is_merge(void)
 	return !access(git_path("MERGE_HEAD"), F_OK);
 }
 
-static int unmerged_files(void)
-{
-	int i;
-	read_cache();
-	for (i = 0; i < active_nr; i++) {
-		struct cache_entry *ce = active_cache[i];
-		if (ce_stage(ce))
-			return 1;
-	}
-	return 0;
-}
-
 static int reset_index_file(const unsigned char *sha1, int is_hard_reset)
 {
 	int i = 0;
@@ -250,7 +238,7 @@ int cmd_reset(int argc, const char **argv, const char *prefix)
 	 * at all, but requires them in a good order.  Other resets reset
 	 * the index file to the tree object we are switching to. */
 	if (reset_type == SOFT) {
-		if (is_merge() || unmerged_files())
+		if (is_merge() || read_cache() < 0 || unmerged_cache())
 			die("Cannot do a soft reset in the middle of a merge.");
 	}
 	else if (reset_index_file(sha1, (reset_type == HARD)))

cache.h

@@ -208,6 +208,7 @@ extern struct index_state the_index;
 #define read_cache_from(path) read_index_from(&the_index, (path))
 #define write_cache(newfd, cache, entries) write_index(&the_index, (newfd))
 #define discard_cache() discard_index(&the_index)
+#define unmerged_cache() unmerged_index(&the_index)
 #define cache_name_pos(name, namelen) index_name_pos(&the_index,(name),(namelen))
 #define add_cache_entry(ce, option) add_index_entry(&the_index, (ce), (option))
 #define remove_cache_entry_at(pos) remove_index_entry_at(&the_index, (pos))
@@ -302,6 +303,7 @@ extern int read_index(struct index_state *);
 extern int read_index_from(struct index_state *, const char *path);
 extern int write_index(struct index_state *, int newfd);
 extern int discard_index(struct index_state *);
+extern int unmerged_index(struct index_state *);
 extern int verify_path(const char *path);
 extern int index_name_exists(struct index_state *istate, const char *name, int namelen);
 extern int index_name_pos(struct index_state *, const char *name, int namelen);

read-cache.c

@@ -1176,6 +1176,16 @@ int discard_index(struct index_state *istate)
 	return 0;
 }
 
+int unmerged_index(struct index_state *istate)
+{
+	int i;
+	for (i = 0; i < istate->cache_nr; i++) {
+		if (ce_stage(istate->cache[i]))
+			return 1;
+	}
+	return 0;
+}
+
 #define WRITE_BUFFER_SIZE 8192
 static unsigned char write_buffer[WRITE_BUFFER_SIZE];
 static unsigned long write_buffer_len;