Merge branch 'mh/abspath'

* mh/abspath:
  t0060: split absolute path test in two to exercise some of it on Windows
  t0060: verify that real_path() removes extra slashes
  real_path(): properly handle nonexistent top-level paths
  t0060: verify that real_path() works correctly with absolute paths
  real_path(): reject the empty string
  t0060: verify that real_path() fails if passed the empty string
  absolute_path(): reject the empty string
  t0060: verify that absolute_path() fails if passed the empty string
  t0060: move tests of real_path() from t0000 to here

abspath.c

@@ -35,15 +35,18 @@ const char *real_path(const char *path)
 	if (path == buf || path == next_buf)
 		return path;
 
+	if (!*path)
+		die("The empty string is not a valid path");
+
 	if (strlcpy(buf, path, PATH_MAX) >= PATH_MAX)
 		die ("Too long path: %.*s", 60, path);
 
 	while (depth--) {
 		if (!is_directory(buf)) {
 			char *last_slash = find_last_dir_sep(buf);
 			if (last_slash) {
-				*last_slash = '\0';
 				last_elem = xstrdup(last_slash + 1);
+				last_slash[1] = '\0';
 			} else {
 				last_elem = xstrdup(buf);
 				*buf = '\0';
@@ -123,7 +126,9 @@ const char *absolute_path(const char *path)
 {
 	static char buf[PATH_MAX + 1];
 
-	if (is_absolute_path(path)) {
+	if (!*path) {
+		die("The empty string is not a valid path");
+	} else if (is_absolute_path(path)) {
 		if (strlcpy(buf, path, PATH_MAX) >= PATH_MAX)
 			die("Too long path: %.*s", 60, path);
 	} else {

t/t0000-basic.sh

@@ -450,24 +450,6 @@ test_expect_success 'update-index D/F conflict' '
 	test $numpath0 = 1
 '
 
-test_expect_success SYMLINKS 'real path works as expected' '
-	mkdir first &&
-	ln -s ../.git first/.git &&
-	mkdir second &&
-	ln -s ../first second/other &&
-	mkdir third &&
-	dir="$(cd .git; pwd -P)" &&
-	dir2=third/../second/other/.git &&
-	test "$dir" = "$(test-path-utils real_path $dir2)" &&
-	file="$dir"/index &&
-	test "$file" = "$(test-path-utils real_path $dir2/index)" &&
-	basename=blub &&
-	test "$dir/$basename" = "$(cd .git && test-path-utils real_path "$basename")" &&
-	ln -s ../first/file .git/syml &&
-	sym="$(cd first; pwd -P)"/file &&
-	test "$sym" = "$(test-path-utils real_path "$dir2/syml")"
-'
-
 test_expect_success 'very long name in the index handled sanely' '
 
 	a=a && # 1

t/t0060-path-utils.sh

@@ -139,4 +139,63 @@ test_expect_success 'strip_path_suffix' '
 	test c:/msysgit = $(test-path-utils strip_path_suffix \
 		c:/msysgit/libexec//git-core libexec/git-core)
 '
+
+test_expect_success 'absolute path rejects the empty string' '
+	test_must_fail test-path-utils absolute_path ""
+'
+
+test_expect_success 'real path rejects the empty string' '
+	test_must_fail test-path-utils real_path ""
+'
+
+test_expect_success POSIX 'real path works on absolute paths 1' '
+	nopath="hopefully-absent-path" &&
+	test "/" = "$(test-path-utils real_path "/")" &&
+	test "/$nopath" = "$(test-path-utils real_path "/$nopath")"
+'
+
+test_expect_success 'real path works on absolute paths 2' '
+	nopath="hopefully-absent-path" &&
+	# Find an existing top-level directory for the remaining tests:
+	d=$(pwd -P | sed -e "s|^\([^/]*/[^/]*\)/.*|\1|") &&
+	test "$d" = "$(test-path-utils real_path "$d")" &&
+	test "$d/$nopath" = "$(test-path-utils real_path "$d/$nopath")"
+'
+
+test_expect_success POSIX 'real path removes extra leading slashes' '
+	nopath="hopefully-absent-path" &&
+	test "/" = "$(test-path-utils real_path "///")" &&
+	test "/$nopath" = "$(test-path-utils real_path "///$nopath")" &&
+	# Find an existing top-level directory for the remaining tests:
+	d=$(pwd -P | sed -e "s|^\([^/]*/[^/]*\)/.*|\1|") &&
+	test "$d" = "$(test-path-utils real_path "//$d")" &&
+	test "$d/$nopath" = "$(test-path-utils real_path "//$d/$nopath")"
+'
+
+test_expect_success 'real path removes other extra slashes' '
+	nopath="hopefully-absent-path" &&
+	# Find an existing top-level directory for the remaining tests:
+	d=$(pwd -P | sed -e "s|^\([^/]*/[^/]*\)/.*|\1|") &&
+	test "$d" = "$(test-path-utils real_path "$d///")" &&
+	test "$d/$nopath" = "$(test-path-utils real_path "$d///$nopath")"
+'
+
+test_expect_success SYMLINKS 'real path works on symlinks' '
+	mkdir first &&
+	ln -s ../.git first/.git &&
+	mkdir second &&
+	ln -s ../first second/other &&
+	mkdir third &&
+	dir="$(cd .git; pwd -P)" &&
+	dir2=third/../second/other/.git &&
+	test "$dir" = "$(test-path-utils real_path $dir2)" &&
+	file="$dir"/index &&
+	test "$file" = "$(test-path-utils real_path $dir2/index)" &&
+	basename=blub &&
+	test "$dir/$basename" = "$(cd .git && test-path-utils real_path "$basename")" &&
+	ln -s ../first/file .git/syml &&
+	sym="$(cd first; pwd -P)"/file &&
+	test "$sym" = "$(test-path-utils real_path "$dir2/syml")"
+'
+
 test_done