Merge branch 'rs/apply-validate-input' into maint

Tighten error checks for invalid "git apply" input.

* rs/apply-validate-input:
  apply: check git diffs for mutually exclusive header lines
  apply: check git diffs for invalid file modes
  apply: check git diffs for missing old filenames

apply.c

@@ -210,6 +210,7 @@ struct patch {
 	unsigned ws_rule;
 	int lines_added, lines_deleted;
 	int score;
+	int extension_linenr; /* first line specifying delete/new/rename/copy */
 	unsigned int is_toplevel_relative:1;
 	unsigned int inaccurate_eof:1;
 	unsigned int is_binary:1;
@@ -1011,20 +1012,27 @@ static int gitdiff_newname(struct apply_state *state,
 				   DIFF_NEW_NAME);
 }
 
+static int parse_mode_line(const char *line, int linenr, unsigned int *mode)
+{
+	char *end;
+	*mode = strtoul(line, &end, 8);
+	if (end == line || !isspace(*end))
+		return error(_("invalid mode on line %d: %s"), linenr, line);
+	return 0;
+}
+
 static int gitdiff_oldmode(struct apply_state *state,
 			   const char *line,
 			   struct patch *patch)
 {
-	patch->old_mode = strtoul(line, NULL, 8);
-	return 0;
+	return parse_mode_line(line, state->linenr, &patch->old_mode);
 }
 
 static int gitdiff_newmode(struct apply_state *state,
 			   const char *line,
 			   struct patch *patch)
 {
-	patch->new_mode = strtoul(line, NULL, 8);
-	return 0;
+	return parse_mode_line(line, state->linenr, &patch->new_mode);
 }
 
 static int gitdiff_delete(struct apply_state *state,
@@ -1138,7 +1146,7 @@ static int gitdiff_index(struct apply_state *state,
 	memcpy(patch->new_sha1_prefix, line, len);
 	patch->new_sha1_prefix[len] = 0;
 	if (*ptr == ' ')
-		patch->old_mode = strtoul(ptr+1, NULL, 8);
+		return gitdiff_oldmode(state, ptr + 1, patch);
 	return 0;
 }
 
@@ -1322,6 +1330,18 @@ static char *git_header_name(struct apply_state *state,
 	}
 }
 
+static int check_header_line(struct apply_state *state, struct patch *patch)
+{
+	int extensions = (patch->is_delete == 1) + (patch->is_new == 1) +
+			 (patch->is_rename == 1) + (patch->is_copy == 1);
+	if (extensions > 1)
+		return error(_("inconsistent header lines %d and %d"),
+			     patch->extension_linenr, state->linenr);
+	if (extensions && !patch->extension_linenr)
+		patch->extension_linenr = state->linenr;
+	return 0;
+}
+
 /* Verify that we recognize the lines following a git header */
 static int parse_git_header(struct apply_state *state,
 			    const char *line,
@@ -1388,6 +1408,8 @@ static int parse_git_header(struct apply_state *state,
 			res = p->fn(state, line + oplen, patch);
 			if (res < 0)
 				return -1;
+			if (check_header_line(state, patch))
+				return -1;
 			if (res > 0)
 				return offset;
 			break;
@@ -1585,7 +1607,8 @@ static int find_header(struct apply_state *state,
 				patch->old_name = xstrdup(patch->def_name);
 				patch->new_name = xstrdup(patch->def_name);
 			}
-			if (!patch->is_delete && !patch->new_name) {
+			if ((!patch->new_name && !patch->is_delete) ||
+			    (!patch->old_name && !patch->is_new)) {
 				error(_("git diff header lacks filename information "
 					     "(line %d)"), state->linenr);
 				return -128;

t/t4129-apply-samemode.sh

@@ -13,7 +13,9 @@ test_expect_success setup '
 	echo modified >file &&
 	git diff --stat -p >patch-0.txt &&
 	chmod +x file &&
-	git diff --stat -p >patch-1.txt
+	git diff --stat -p >patch-1.txt &&
+	sed "s/^\(new mode \).*/\1/" <patch-1.txt >patch-empty-mode.txt &&
+	sed "s/^\(new mode \).*/\1garbage/" <patch-1.txt >patch-bogus-mode.txt
 '
 
 test_expect_success FILEMODE 'same mode (no index)' '
@@ -59,4 +61,16 @@ test_expect_success FILEMODE 'mode update (index only)' '
 	git ls-files -s file | grep "^100755"
 '
 
+test_expect_success FILEMODE 'empty mode is rejected' '
+	git reset --hard &&
+	test_must_fail git apply patch-empty-mode.txt 2>err &&
+	test_i18ngrep "invalid mode" err
+'
+
+test_expect_success FILEMODE 'bogus mode is rejected' '
+	git reset --hard &&
+	test_must_fail git apply patch-bogus-mode.txt 2>err &&
+	test_i18ngrep "invalid mode" err
+'
+
 test_done

t/t4133-apply-filenames.sh

@@ -35,4 +35,28 @@ test_expect_success 'apply diff with inconsistent filenames in headers' '
 	test_i18ngrep "inconsistent old filename" err
 '
 
+test_expect_success 'apply diff with new filename missing from headers' '
+	cat >missing_new_filename.diff <<-\EOF &&
+	diff --git a/f b/f
+	index 0000000..d00491f
+	--- a/f
+	@@ -0,0 +1 @@
+	+1
+	EOF
+	test_must_fail git apply missing_new_filename.diff 2>err &&
+	test_i18ngrep "lacks filename information" err
+'
+
+test_expect_success 'apply diff with old filename missing from headers' '
+	cat >missing_old_filename.diff <<-\EOF &&
+	diff --git a/f b/f
+	index d00491f..0000000
+	+++ b/f
+	@@ -1 +0,0 @@
+	-1
+	EOF
+	test_must_fail git apply missing_old_filename.diff 2>err &&
+	test_i18ngrep "lacks filename information" err
+'
+
 test_done

t/t4136-apply-check.sh

@@ -29,4 +29,22 @@ test_expect_success 'apply exits non-zero with no-op patch' '
 	test_must_fail git apply --check input
 '
 
+test_expect_success 'invalid combination: create and copy' '
+	test_must_fail git apply --check - <<-\EOF
+	diff --git a/1 b/2
+	new file mode 100644
+	copy from 1
+	copy to 2
+	EOF
+'
+
+test_expect_success 'invalid combination: create and rename' '
+	test_must_fail git apply --check - <<-\EOF
+	diff --git a/1 b/2
+	new file mode 100644
+	rename from 1
+	rename to 2
+	EOF
+'
+
 test_done