string_list_longest_prefix(): remove function

This function was added in f103f95b11 in
the erroneous expectation that it would be used in the
reimplementation of longest_ancestor_length().  But it turned out to
be easier to use a function specialized for comparing path prefixes
(i.e., one that knows about slashes and root paths) than to prepare
the paths in such a way that a generic string prefix comparison
function can be used.  So delete string_list_longest_prefix() and its
documentation and test cases.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Jeff King <peff@peff.net>

Documentation/technical/api-string-list.txt

@@ -75,14 +75,6 @@ Functions
 	to be deleted.  Preserve the order of the items that are
 	retained.
 
-`string_list_longest_prefix`::
-
-	Return the longest string within a string_list that is a
-	prefix (in the sense of prefixcmp()) of the specified string,
-	or NULL if no such prefix exists.  This function does not
-	require the string_list to be sorted (it does a linear
-	search).
-
 `print_string_list`::
 
 	Dump a string_list to stdout, useful mainly for debugging purposes. It

string-list.c

@@ -136,26 +136,6 @@ void filter_string_list(struct string_list *list, int free_util,
 	list->nr = dst;
 }
 
-char *string_list_longest_prefix(const struct string_list *prefixes,
-				 const char *string)
-{
-	int i, max_len = -1;
-	char *retval = NULL;
-
-	for (i = 0; i < prefixes->nr; i++) {
-		char *prefix = prefixes->items[i].string;
-		if (!prefixcmp(string, prefix)) {
-			int len = strlen(prefix);
-			if (len > max_len) {
-				retval = prefix;
-				max_len = len;
-			}
-		}
-	}
-
-	return retval;
-}
-
 void string_list_clear(struct string_list *list, int free_util)
 {
 	if (list->items) {

string-list.h

@@ -38,14 +38,6 @@ int for_each_string_list(struct string_list *list,
 void filter_string_list(struct string_list *list, int free_util,
 			string_list_each_func_t want, void *cb_data);
 
-/*
- * Return the longest string in prefixes that is a prefix (in the
- * sense of prefixcmp()) of string, or NULL if no such prefix exists.
- * This function does not require the string_list to be sorted (it
- * does a linear search).
- */
-char *string_list_longest_prefix(const struct string_list *prefixes, const char *string);
-
 
 /* Use these functions only on sorted lists: */
 int string_list_has_string(const struct string_list *list, const char *string);

t/t0063-string-list.sh

@@ -17,14 +17,6 @@ test_split () {
 	"
 }
 
-test_longest_prefix () {
-	test "$(test-string-list longest_prefix "$1" "$2")" = "$3"
-}
-
-test_no_longest_prefix () {
-	test_must_fail test-string-list longest_prefix "$1" "$2"
-}
-
 test_split "foo:bar:baz" ":" "-1" <<EOF
 3
 [0]: "foo"
@@ -96,26 +88,4 @@ test_expect_success "test remove_duplicates" '
 	test a:b:c = "$(test-string-list remove_duplicates a:a:a:b:b:b:c:c:c)"
 '
 
-test_expect_success "test longest_prefix" '
-	test_no_longest_prefix - '' &&
-	test_no_longest_prefix - x &&
-	test_longest_prefix "" x "" &&
-	test_longest_prefix x x x &&
-	test_longest_prefix "" foo "" &&
-	test_longest_prefix : foo "" &&
-	test_longest_prefix f foo f &&
-	test_longest_prefix foo foobar foo &&
-	test_longest_prefix foo foo foo &&
-	test_no_longest_prefix bar foo &&
-	test_no_longest_prefix bar:bar foo &&
-	test_no_longest_prefix foobar foo &&
-	test_longest_prefix foo:bar foo foo &&
-	test_longest_prefix foo:bar bar bar &&
-	test_longest_prefix foo::bar foo foo &&
-	test_longest_prefix foo:foobar foo foo &&
-	test_longest_prefix foobar:foo foo foo &&
-	test_longest_prefix foo: bar "" &&
-	test_longest_prefix :foo bar ""
-'
-
 test_done

test-string-list.c

@@ -97,26 +97,6 @@ int main(int argc, char **argv)
 		return 0;
 	}
 
-	if (argc == 4 && !strcmp(argv[1], "longest_prefix")) {
-		/* arguments: <colon-separated-prefixes>|- <string> */
-		struct string_list prefixes = STRING_LIST_INIT_DUP;
-		int retval;
-		const char *prefix_string = argv[2];
-		const char *string = argv[3];
-		const char *match;
-
-		parse_string_list(&prefixes, prefix_string);
-		match = string_list_longest_prefix(&prefixes, string);
-		if (match) {
-			printf("%s\n", match);
-			retval = 0;
-		}
-		else
-			retval = 1;
-		string_list_clear(&prefixes, 0);
-		return retval;
-	}
-
 	fprintf(stderr, "%s: unknown function name: %s\n", argv[0],
 		argv[1] ? argv[1] : "(there was none)");
 	return 1;