Merge branch 'cc/apply-am'

"git am" has been taught to make an internal call to "git apply"'s
innards without spawning the latter as a separate process.

* cc/apply-am: (41 commits)
  builtin/am: use apply API in run_apply()
  apply: learn to use a different index file
  apply: pass apply state to build_fake_ancestor()
  apply: refactor `git apply` option parsing
  apply: change error_routine when silent
  usage: add get_error_routine() and get_warn_routine()
  usage: add set_warn_routine()
  apply: don't print on stdout in verbosity_silent mode
  apply: make it possible to silently apply
  apply: use error_errno() where possible
  apply: make some parsing functions static again
  apply: move libified code from builtin/apply.c to apply.{c,h}
  apply: rename and move opt constants to apply.h
  builtin/apply: rename option parsing functions
  builtin/apply: make create_one_file() return -1 on error
  builtin/apply: make try_create_file() return -1 on error
  builtin/apply: make write_out_results() return -1 on error
  builtin/apply: make write_out_one_result() return -1 on error
  builtin/apply: make create_file() return -1 on error
  builtin/apply: make add_index_file() return -1 on error
  ...

Makefile

@@ -696,6 +696,7 @@ LIB_OBJS += abspath.o
 LIB_OBJS += advice.o
 LIB_OBJS += alias.o
 LIB_OBJS += alloc.o
+LIB_OBJS += apply.o
 LIB_OBJS += archive.o
 LIB_OBJS += archive-tar.o
 LIB_OBJS += archive-zip.o

apply.h

@@ -0,0 +1,137 @@
+#ifndef APPLY_H
+#define APPLY_H
+
+enum apply_ws_error_action {
+	nowarn_ws_error,
+	warn_on_ws_error,
+	die_on_ws_error,
+	correct_ws_error
+};
+
+enum apply_ws_ignore {
+	ignore_ws_none,
+	ignore_ws_change
+};
+
+enum apply_verbosity {
+	verbosity_silent = -1,
+	verbosity_normal = 0,
+	verbosity_verbose = 1
+};
+
+/*
+ * We need to keep track of how symlinks in the preimage are
+ * manipulated by the patches.  A patch to add a/b/c where a/b
+ * is a symlink should not be allowed to affect the directory
+ * the symlink points at, but if the same patch removes a/b,
+ * it is perfectly fine, as the patch removes a/b to make room
+ * to create a directory a/b so that a/b/c can be created.
+ *
+ * See also "struct string_list symlink_changes" in "struct
+ * apply_state".
+ */
+#define APPLY_SYMLINK_GOES_AWAY 01
+#define APPLY_SYMLINK_IN_RESULT 02
+
+struct apply_state {
+	const char *prefix;
+	int prefix_length;
+
+	/* These are lock_file related */
+	struct lock_file *lock_file;
+	int newfd;
+
+	/* These control what gets looked at and modified */
+	int apply; /* this is not a dry-run */
+	int cached; /* apply to the index only */
+	int check; /* preimage must match working tree, don't actually apply */
+	int check_index; /* preimage must match the indexed version */
+	int update_index; /* check_index && apply */
+
+	/* These control cosmetic aspect of the output */
+	int diffstat; /* just show a diffstat, and don't actually apply */
+	int numstat; /* just show a numeric diffstat, and don't actually apply */
+	int summary; /* just report creation, deletion, etc, and don't actually apply */
+
+	/* These boolean parameters control how the apply is done */
+	int allow_overlap;
+	int apply_in_reverse;
+	int apply_with_reject;
+	int no_add;
+	int threeway;
+	int unidiff_zero;
+	int unsafe_paths;
+
+	/* Other non boolean parameters */
+	const char *index_file;
+	enum apply_verbosity apply_verbosity;
+	const char *fake_ancestor;
+	const char *patch_input_file;
+	int line_termination;
+	struct strbuf root;
+	int p_value;
+	int p_value_known;
+	unsigned int p_context;
+
+	/* Exclude and include path parameters */
+	struct string_list limit_by_name;
+	int has_include;
+
+	/* Various "current state" */
+	int linenr; /* current line number */
+	struct string_list symlink_changes; /* we have to track symlinks */
+
+	/*
+	 * For "diff-stat" like behaviour, we keep track of the biggest change
+	 * we've seen, and the longest filename. That allows us to do simple
+	 * scaling.
+	 */
+	int max_change;
+	int max_len;
+
+	/*
+	 * Records filenames that have been touched, in order to handle
+	 * the case where more than one patches touch the same file.
+	 */
+	struct string_list fn_table;
+
+	/*
+	 * This is to save reporting routines before using
+	 * set_error_routine() or set_warn_routine() to install muting
+	 * routines when in verbosity_silent mode.
+	 */
+	void (*saved_error_routine)(const char *err, va_list params);
+	void (*saved_warn_routine)(const char *warn, va_list params);
+
+	/* These control whitespace errors */
+	enum apply_ws_error_action ws_error_action;
+	enum apply_ws_ignore ws_ignore_action;
+	const char *whitespace_option;
+	int whitespace_error;
+	int squelch_whitespace_errors;
+	int applied_after_fixing_ws;
+};
+
+extern int apply_parse_options(int argc, const char **argv,
+			       struct apply_state *state,
+			       int *force_apply, int *options,
+			       const char * const *apply_usage);
+extern int init_apply_state(struct apply_state *state,
+			    const char *prefix,
+			    struct lock_file *lock_file);
+extern void clear_apply_state(struct apply_state *state);
+extern int check_apply_state(struct apply_state *state, int force_apply);
+
+/*
+ * Some aspects of the apply behavior are controlled by the following
+ * bits in the "options" parameter passed to apply_all_patches().
+ */
+#define APPLY_OPT_INACCURATE_EOF	(1<<0) /* accept inaccurate eof */
+#define APPLY_OPT_RECOUNT		(1<<1) /* accept inaccurate line count */
+
+extern int apply_all_patches(struct apply_state *state,
+			     int argc,
+			     const char **argv,
+			     int options);
+
+#endif

builtin/am.c

@@ -28,6 +28,7 @@
 #include "rerere.h"
 #include "prompt.h"
 #include "mailinfo.h"
+#include "apply.h"
 #include "string-list.h"
 
 /**
@@ -1509,40 +1510,60 @@ static int parse_mail_rebase(struct am_state *state, const char *mail)
  */
 static int run_apply(const struct am_state *state, const char *index_file)
 {
-	struct child_process cp = CHILD_PROCESS_INIT;
+	struct argv_array apply_paths = ARGV_ARRAY_INIT;
+	struct argv_array apply_opts = ARGV_ARRAY_INIT;
+	struct apply_state apply_state;
+	int res, opts_left;
+	static struct lock_file lock_file;
+	int force_apply = 0;
+	int options = 0;
 
-	cp.git_cmd = 1;
+	if (init_apply_state(&apply_state, NULL, &lock_file))
+		die("BUG: init_apply_state() failed");
 
-	if (index_file)
-		argv_array_pushf(&cp.env_array, "GIT_INDEX_FILE=%s", index_file);
+	argv_array_push(&apply_opts, "apply");
+	argv_array_pushv(&apply_opts, state->git_apply_opts.argv);
+
+	opts_left = apply_parse_options(apply_opts.argc, apply_opts.argv,
+					&apply_state, &force_apply, &options,
+					NULL);
+
+	if (opts_left != 0)
+		die("unknown option passed through to git apply");
+
+	if (index_file) {
+		apply_state.index_file = index_file;
+		apply_state.cached = 1;
+	} else
+		apply_state.check_index = 1;
 
 	/*
 	 * If we are allowed to fall back on 3-way merge, don't give false
 	 * errors during the initial attempt.
 	 */
-	if (state->threeway && !index_file) {
-		cp.no_stdout = 1;
-		cp.no_stderr = 1;
+	if (state->threeway && !index_file)
+		apply_state.apply_verbosity = verbosity_silent;
+
+	if (check_apply_state(&apply_state, force_apply))
+		die("BUG: check_apply_state() failed");
+
+	argv_array_push(&apply_paths, am_path(state, "patch"));
+
+	res = apply_all_patches(&apply_state, apply_paths.argc, apply_paths.argv, options);
+
+	argv_array_clear(&apply_paths);
+	argv_array_clear(&apply_opts);
+	clear_apply_state(&apply_state);
+
+	if (res)
+		return res;
+
+	if (index_file) {
+		/* Reload index as apply_all_patches() will have modified it. */
+		discard_cache();
+		read_cache_from(index_file);
 	}
 
-	argv_array_push(&cp.args, "apply");
-
-	argv_array_pushv(&cp.args, state->git_apply_opts.argv);
-
-	if (index_file)
-		argv_array_push(&cp.args, "--cached");
-	else
-		argv_array_push(&cp.args, "--index");
-
-	argv_array_push(&cp.args, am_path(state, "patch"));
-
-	if (run_command(&cp))
-		return -1;
-
-	/* Reload index as git-apply will have modified it. */
-	discard_cache();
-	read_cache_from(index_file ? index_file : get_index_file());
-
 	return 0;
 }
 

git-compat-util.h

@@ -441,6 +441,9 @@ static inline int const_error(void)
 
 extern void set_die_routine(NORETURN_PTR void (*routine)(const char *err, va_list params));
 extern void set_error_routine(void (*routine)(const char *err, va_list params));
+extern void (*get_error_routine(void))(const char *err, va_list params);
+extern void set_warn_routine(void (*routine)(const char *warn, va_list params));
+extern void (*get_warn_routine(void))(const char *warn, va_list params);
 extern void set_die_is_recursing_routine(int (*routine)(void));
 extern void set_error_handle(FILE *);
 

t/t4012-diff-binary.sh

@@ -68,7 +68,7 @@ test_expect_success C_LOCALE_OUTPUT 'apply detecting corrupt patch correctly' '
 	sed -e "s/-CIT/xCIT/" <output >broken &&
 	test_must_fail git apply --stat --summary broken 2>detected &&
 	detected=$(cat detected) &&
-	detected=$(expr "$detected" : "fatal.*at line \\([0-9]*\\)\$") &&
+	detected=$(expr "$detected" : "error.*at line \\([0-9]*\\)\$") &&
 	detected=$(sed -ne "${detected}p" broken) &&
 	test "$detected" = xCIT
 '
@@ -77,7 +77,7 @@ test_expect_success C_LOCALE_OUTPUT 'apply detecting corrupt patch correctly' '
 	git diff --binary | sed -e "s/-CIT/xCIT/" >broken &&
 	test_must_fail git apply --stat --summary broken 2>detected &&
 	detected=$(cat detected) &&
-	detected=$(expr "$detected" : "fatal.*at line \\([0-9]*\\)\$") &&
+	detected=$(expr "$detected" : "error.*at line \\([0-9]*\\)\$") &&
 	detected=$(sed -ne "${detected}p" broken) &&
 	test "$detected" = xCIT
 '

t/t4254-am-corrupt.sh

@@ -29,7 +29,7 @@ test_expect_success 'try to apply corrupted patch' '
 '
 
 test_expect_success 'compare diagnostic; ensure file is still here' '
-	echo "fatal: git diff header lacks filename information (line 4)" >expected &&
+	echo "error: git diff header lacks filename information (line 4)" >expected &&
 	test_path_is_file f &&
 	test_cmp expected actual
 '

usage.c

@@ -70,6 +70,21 @@ void set_error_routine(void (*routine)(const char *err, va_list params))
 	error_routine = routine;
 }
 
+void (*get_error_routine(void))(const char *err, va_list params)
+{
+	return error_routine;
+}
+
+void set_warn_routine(void (*routine)(const char *warn, va_list params))
+{
+	warn_routine = routine;
+}
+
+void (*get_warn_routine(void))(const char *warn, va_list params)
+{
+	return warn_routine;
+}
+
 void set_die_is_recursing_routine(int (*routine)(void))
 {
 	die_is_recursing = routine;