Merge branch 'ml/trace' into next

* ml/trace:
  GIT_TRACE: fix a mixed declarations and code warning
  GIT_TRACE: show which built-in/external commands are executed
  Disable color detection during format-patch
  git-cvsexportcommit can't handle merge commits correctly
  Using 'perl' in *.sh
  sed -e '/RE/r rfile/' needs space in 'r rfile'
  Close the index file between writing and committing
  colored diff: diff.color = auto fix

Documentation/git.txt

@@ -615,6 +615,13 @@ git Diffs
 	gitlink:git-diff-files[1];
 	gitlink:git-diff-tree[1]
 
+other
+~~~~~
+'GIT_TRACE'::
+	If this variable is set git will print `trace:` messages on
+	stderr telling about alias expansion, built-in command
+	execution and external command execution.
+
 Discussion[[Discussion]]
 ------------------------
 include::README[]

Makefile

@@ -546,6 +546,7 @@ common-cmds.h: Documentation/git-*.txt
 $(patsubst %.sh,%,$(SCRIPT_SH)) : % : %.sh
 	rm -f $@ $@+
 	sed -e '1s|#!.*/sh|#!$(SHELL_PATH_SQ)|' \
+	    -e 's|@@PERL@@|$(PERL_PATH_SQ)|g' \
 	    -e 's/@@GIT_VERSION@@/$(GIT_VERSION)/g' \
 	    -e 's/@@NO_CURL@@/$(NO_CURL)/g' \
 	    -e 's/@@NO_PYTHON@@/$(NO_PYTHON)/g' \
@@ -589,9 +590,9 @@ git-instaweb: git-instaweb.sh gitweb/gitweb.cgi gitweb/gitweb.css
 	    -e 's/@@GIT_VERSION@@/$(GIT_VERSION)/g' \
 	    -e 's/@@NO_CURL@@/$(NO_CURL)/g' \
 	    -e 's/@@NO_PYTHON@@/$(NO_PYTHON)/g' \
-	    -e '/@@GITWEB_CGI@@/rgitweb/gitweb.cgi' \
+	    -e '/@@GITWEB_CGI@@/r gitweb/gitweb.cgi' \
 	    -e '/@@GITWEB_CGI@@/d' \
-	    -e '/@@GITWEB_CSS@@/rgitweb/gitweb.css' \
+	    -e '/@@GITWEB_CSS@@/r gitweb/gitweb.css' \
 	    -e '/@@GITWEB_CSS@@/d' \
 	    $@.sh > $@+
 	chmod +x $@+

builtin-add.c

@@ -181,7 +181,7 @@ int cmd_add(int argc, const char **argv, char **envp)
 
 	if (active_cache_changed) {
 		if (write_cache(newfd, active_cache, active_nr) ||
-		    commit_lock_file(&lock_file))
+		    close(newfd) || commit_lock_file(&lock_file))
 			die("Unable to write new index file");
 	}
 

builtin-apply.c

@@ -2323,7 +2323,7 @@ int cmd_apply(int argc, const char **argv, char **envp)
 
 	if (write_index) {
 		if (write_cache(newfd, active_cache, active_nr) ||
-		    commit_lock_file(&lock_file))
+		    close(newfd) || commit_lock_file(&lock_file))
 			die("Unable to write new index file");
 	}
 

builtin-log.c

@@ -105,6 +105,9 @@ static int git_format_config(const char *var, const char *value)
 		strcat(extra_headers, value);
 		return 0;
 	}
+	if (!strcmp(var, "diff.color")) {
+		return 0;
+	}
 	return git_diff_ui_config(var, value);
 }
 

builtin-read-tree.c

@@ -1038,7 +1038,7 @@ int cmd_read_tree(int argc, const char **argv, char **envp)
 	}
 
 	if (write_cache(newfd, active_cache, active_nr) ||
-	    commit_lock_file(&lock_file))
+	    close(newfd) || commit_lock_file(&lock_file))
 		die("unable to write new index file");
 	return 0;
 }

builtin-rm.c

@@ -147,7 +147,7 @@ int cmd_rm(int argc, const char **argv, char **envp)
 
 	if (active_cache_changed) {
 		if (write_cache(newfd, active_cache, active_nr) ||
-		    commit_lock_file(&lock_file))
+		    close(newfd) || commit_lock_file(&lock_file))
 			die("Unable to write new index file");
 	}
 

builtin-update-index.c

@@ -648,7 +648,7 @@ int cmd_update_index(int argc, const char **argv, char **envp)
  finish:
 	if (active_cache_changed) {
 		if (write_cache(newfd, active_cache, active_nr) ||
-		    commit_lock_file(lock_file))
+		    close(newfd) || commit_lock_file(lock_file))
 			die("Unable to write new index file");
 	}
 

builtin-write-tree.c

@@ -35,7 +35,8 @@ int write_tree(unsigned char *sha1, int missing_ok, const char *prefix)
 				      missing_ok, 0) < 0)
 			die("git-write-tree: error building trees");
 		if (0 <= newfd) {
-			if (!write_cache(newfd, active_cache, active_nr))
+			if (!write_cache(newfd, active_cache, active_nr)
+					&& !close(newfd))
 				commit_lock_file(lock_file);
 		}
 		/* Not being able to write is fine -- we are only interested

checkout-index.c

@@ -311,7 +311,7 @@ int main(int argc, char **argv)
 
 	if (0 <= newfd &&
 	    (write_cache(newfd, active_cache, active_nr) ||
-	     commit_lock_file(&lock_file)))
+	     close(newfd) || commit_lock_file(&lock_file)))
 		die("Unable to write new index file");
 	return 0;
 }

diff.c

@@ -117,8 +117,14 @@ int git_diff_ui_config(const char *var, const char *value)
 	if (!strcmp(var, "diff.color")) {
 		if (!value)
 			diff_use_color_default = 1; /* bool */
-		else if (!strcasecmp(value, "auto"))
-			diff_use_color_default = isatty(1);
+		else if (!strcasecmp(value, "auto")) {
+			diff_use_color_default = 0;
+			if (isatty(1)) {
+				char *term = getenv("TERM");
+				if (term && strcmp(term, "dumb"))
+					diff_use_color_default = 1;
+			}
+		}
 		else if (!strcasecmp(value, "never"))
 			diff_use_color_default = 0;
 		else if (!strcasecmp(value, "always"))

exec_cmd.c

@@ -1,5 +1,6 @@
 #include "cache.h"
 #include "exec_cmd.h"
+#include "quote.h"
 #define MAX_ARGS	32
 
 extern char **environ;
@@ -96,9 +97,27 @@ int execv_git_cmd(const char **argv)
 		tmp = argv[0];
 		argv[0] = git_command;
 
+		if (getenv("GIT_TRACE")) {
+			const char **p = argv;
+			fputs("trace: exec:", stderr);
+			while (*p) {
+				fputc(' ', stderr);
+				sq_quote_print(stderr, *p);
+				++p;
+			}
+			putc('\n', stderr);
+			fflush(stderr);
+		}
+
 		/* execve() can only ever return if it fails */
 		execve(git_command, (char **)argv, environ);
 
+		if (getenv("GIT_TRACE")) {
+			fprintf(stderr, "trace: exec failed: %s\n",
+				strerror(errno));
+			fflush(stderr);
+		}
+
 		argv[0] = tmp;
 	}
 	return -1;

git-bisect.sh

@@ -13,7 +13,7 @@ git bisect log			show bisect log.'
 . git-sh-setup
 
 sq() {
-	perl -e '
+	@@PERL@@ -e '
 		for (@ARGV) {
 			s/'\''/'\'\\\\\'\''/g;
 			print " '\''$_'\''";

git-clone.sh

@@ -324,7 +324,7 @@ test -d "$GIT_DIR/refs/reference-tmp" && rm -fr "$GIT_DIR/refs/reference-tmp"
 if test -f "$GIT_DIR/CLONE_HEAD"
 then
 	# Read git-fetch-pack -k output and store the remote branches.
-	perl -e "$copy_refs" "$GIT_DIR" "$use_separate_remote" "$origin"
+	@@PERL@@ -e "$copy_refs" "$GIT_DIR" "$use_separate_remote" "$origin"
 fi
 
 cd "$D" || exit

git-commit.sh

@@ -147,7 +147,7 @@ run_status () {
 	    git-ls-files -z --others $option \
 		--exclude-per-directory=.gitignore
 	fi |
-	perl -e '$/ = "\0";
+	@@PERL@@ -e '$/ = "\0";
 	    my $shown = 0;
 	    while (<>) {
 		chomp;

git-cvsexportcommit.perl

@@ -63,15 +63,15 @@ foreach my $p (@commit) {
 }
 
 if ($parent) {
+    my $found;
     # double check that it's a valid parent
     foreach my $p (@parents) {
-	my $found;
 	if ($p eq $parent) {
 	    $found = 1;
 	    last;
 	}; # found it
-	die "Did not find $parent in the parents for this commit!";
     }
+    die "Did not find $parent in the parents for this commit!" if !$found;
 } else { # we don't have a parent from the cmdline...
     if (@parents == 1) { # it's safe to get it from the commit
 	$parent = $parents[0];

git-fetch.sh

@@ -278,7 +278,7 @@ fetch_main () {
 	  head="ref: $remote_name"
 	  while (expr "z$head" : "zref:" && expr $depth \< $max_depth) >/dev/null
 	  do
-	    remote_name_quoted=$(perl -e '
+	    remote_name_quoted=$(@@PERL@@ -e '
 	      my $u = $ARGV[0];
               $u =~ s/^ref:\s*//;
 	      $u =~ s{([^-a-zA-Z0-9/.])}{sprintf"%%%02x",ord($1)}eg;

git-rebase.sh

@@ -311,7 +311,7 @@ echo "$prev_head" > "$dotest/prev_head"
 
 msgnum=0
 for cmt in `git-rev-list --no-merges "$upstream"..ORIG_HEAD \
-			| perl -e 'print reverse <>'`
+			| @@PERL@@ -e 'print reverse <>'`
 do
 	msgnum=$(($msgnum + 1))
 	echo "$cmt" > "$dotest/cmt.$msgnum"

git.c

@@ -11,6 +11,7 @@
 #include "git-compat-util.h"
 #include "exec_cmd.h"
 #include "cache.h"
+#include "quote.h"
 
 #include "builtin.h"
 
@@ -120,6 +121,18 @@ static int handle_alias(int *argcp, const char ***argv)
 			if (!strcmp(alias_command, new_argv[0]))
 				die("recursive alias: %s", alias_command);
 
+			if (getenv("GIT_TRACE")) {
+				int i;
+				fprintf(stderr, "trace: alias expansion: %s =>",
+					alias_command);
+				for (i = 0; i < count; ++i) {
+					fputc(' ', stderr);
+					sq_quote_print(stderr, new_argv[i]);
+				}
+				fputc('\n', stderr);
+				fflush(stderr);
+			}
+
 			/* insert after command name */
 			if (*argcp > 1) {
 				new_argv = realloc(new_argv, sizeof(char*) *
@@ -202,6 +215,18 @@ static void handle_internal_command(int argc, const char **argv, char **envp)
 		struct cmd_struct *p = commands+i;
 		if (strcmp(p->cmd, cmd))
 			continue;
+
+		if (getenv("GIT_TRACE")) {
+			int i;
+			fprintf(stderr, "trace: built-in: git");
+			for (i = 0; i < argc; ++i) {
+				fputc(' ', stderr);
+				sq_quote_print(stderr, argv[i]);
+			}
+			putc('\n', stderr);
+			fflush(stderr);
+		}
+
 		exit(p->fn(argc, argv, envp));
 	}
 }

quote.c

@@ -45,6 +45,23 @@ size_t sq_quote_buf(char *dst, size_t n, const char *src)
 	return len;
 }
 
+void sq_quote_print(FILE *stream, const char *src)
+{
+	char c;
+
+	fputc('\'', stream);
+	while ((c = *src++)) {
+		if (need_bs_quote(c)) {
+			fputs("'\\", stream);
+			fputc(c, stream);
+			fputc('\'', stream);
+		} else {
+			fputc(c, stream);
+		}
+	}
+	fputc('\'', stream);
+}
+
 char *sq_quote(const char *src)
 {
 	char *buf;

quote.h

@@ -29,6 +29,7 @@
  */
 
 extern char *sq_quote(const char *src);
+extern void sq_quote_print(FILE *stream, const char *src);
 extern size_t sq_quote_buf(char *dst, size_t n, const char *src);
 
 /* This unwraps what sq_quote() produces in place, but returns