shrink git-shell by avoiding redundant dependencies

A lot of modules that have nothing to do with git-shell functionality
were linked in, bloating git-shell more than 8 times.

This patch cuts off redundant dependencies by:
1. providing stubs for three functions that make no sense for git-shell;
2. moving quote_path_fully from environment.c to quote.c to make the
   later self sufficient;
3. moving make_absolute_path into a new separate file.

The following numbers have been received with the default optimization
settings on master using GCC 4.1.2:

Before:
   text    data     bss     dec     hex filename
 143915    1348   93168  238431   3a35f git-shell

After:
   text    data     bss     dec     hex filename
  17670     788    8232   26690    6842 git-shell

Signed-off-by: Junio C Hamano <gitster@pobox.com>

Makefile

@@ -378,6 +378,7 @@ LIB_H += unpack-trees.h
 LIB_H += utf8.h
 LIB_H += wt-status.h
 
+LIB_OBJS += abspath.o
 LIB_OBJS += alias.o
 LIB_OBJS += alloc.o
 LIB_OBJS += archive.o

abspath.c

@@ -0,0 +1,68 @@
+#include "cache.h"
+
+/* We allow "recursive" symbolic links. Only within reason, though. */
+#define MAXDEPTH 5
+
+const char *make_absolute_path(const char *path)
+{
+	static char bufs[2][PATH_MAX + 1], *buf = bufs[0], *next_buf = bufs[1];
+	char cwd[1024] = "";
+	int buf_index = 1, len;
+
+	int depth = MAXDEPTH;
+	char *last_elem = NULL;
+	struct stat st;
+
+	if (strlcpy(buf, path, PATH_MAX) >= PATH_MAX)
+		die ("Too long path: %.*s", 60, path);
+
+	while (depth--) {
+		if (stat(buf, &st) || !S_ISDIR(st.st_mode)) {
+			char *last_slash = strrchr(buf, '/');
+			if (last_slash) {
+				*last_slash = '\0';
+				last_elem = xstrdup(last_slash + 1);
+			} else {
+				last_elem = xstrdup(buf);
+				*buf = '\0';
+			}
+		}
+
+		if (*buf) {
+			if (!*cwd && !getcwd(cwd, sizeof(cwd)))
+				die ("Could not get current working directory");
+
+			if (chdir(buf))
+				die ("Could not switch to '%s'", buf);
+		}
+		if (!getcwd(buf, PATH_MAX))
+			die ("Could not get current working directory");
+
+		if (last_elem) {
+			int len = strlen(buf);
+			if (len + strlen(last_elem) + 2 > PATH_MAX)
+				die ("Too long path name: '%s/%s'",
+						buf, last_elem);
+			buf[len] = '/';
+			strcpy(buf + len + 1, last_elem);
+			free(last_elem);
+			last_elem = NULL;
+		}
+
+		if (!lstat(buf, &st) && S_ISLNK(st.st_mode)) {
+			len = readlink(buf, next_buf, PATH_MAX);
+			if (len < 0)
+				die ("Invalid symlink: %s", buf);
+			next_buf[len] = '\0';
+			buf = next_buf;
+			buf_index = 1 - buf_index;
+			next_buf = bufs[buf_index];
+		} else
+			break;
+	}
+
+	if (*cwd && chdir(cwd))
+		die ("Could not change back to '%s'", cwd);
+
+	return buf;
+}

environment.c

@@ -13,7 +13,6 @@ char git_default_email[MAX_GITNAME];
 char git_default_name[MAX_GITNAME];
 int user_ident_explicitly_given;
 int trust_executable_bit = 1;
-int quote_path_fully = 1;
 int has_symlinks = 1;
 int ignore_case;
 int assume_unchanged;

path.c

@@ -327,9 +327,6 @@ const char *make_nonrelative_path(const char *path)
 	return buf;
 }
 
-/* We allow "recursive" symbolic links. Only within reason, though. */
-#define MAXDEPTH 5
-
 const char *make_relative_path(const char *abs, const char *base)
 {
 	static char buf[PATH_MAX + 1];
@@ -346,67 +343,3 @@ const char *make_relative_path(const char *abs, const char *base)
 	strcpy(buf, abs + baselen);
 	return buf;
 }
-
-const char *make_absolute_path(const char *path)
-{
-	static char bufs[2][PATH_MAX + 1], *buf = bufs[0], *next_buf = bufs[1];
-	char cwd[1024] = "";
-	int buf_index = 1, len;
-
-	int depth = MAXDEPTH;
-	char *last_elem = NULL;
-	struct stat st;
-
-	if (strlcpy(buf, path, PATH_MAX) >= PATH_MAX)
-		die ("Too long path: %.*s", 60, path);
-
-	while (depth--) {
-		if (stat(buf, &st) || !S_ISDIR(st.st_mode)) {
-			char *last_slash = strrchr(buf, '/');
-			if (last_slash) {
-				*last_slash = '\0';
-				last_elem = xstrdup(last_slash + 1);
-			} else {
-				last_elem = xstrdup(buf);
-				*buf = '\0';
-			}
-		}
-
-		if (*buf) {
-			if (!*cwd && !getcwd(cwd, sizeof(cwd)))
-				die ("Could not get current working directory");
-
-			if (chdir(buf))
-				die ("Could not switch to '%s'", buf);
-		}
-		if (!getcwd(buf, PATH_MAX))
-			die ("Could not get current working directory");
-
-		if (last_elem) {
-			int len = strlen(buf);
-			if (len + strlen(last_elem) + 2 > PATH_MAX)
-				die ("Too long path name: '%s/%s'",
-						buf, last_elem);
-			buf[len] = '/';
-			strcpy(buf + len + 1, last_elem);
-			free(last_elem);
-			last_elem = NULL;
-		}
-
-		if (!lstat(buf, &st) && S_ISLNK(st.st_mode)) {
-			len = readlink(buf, next_buf, PATH_MAX);
-			if (len < 0)
-				die ("Invalid symlink: %s", buf);
-			next_buf[len] = '\0';
-			buf = next_buf;
-			buf_index = 1 - buf_index;
-			next_buf = bufs[buf_index];
-		} else
-			break;
-	}
-
-	if (*cwd && chdir(cwd))
-		die ("Could not change back to '%s'", cwd);
-
-	return buf;
-}

quote.c

@@ -1,6 +1,8 @@
 #include "cache.h"
 #include "quote.h"
 
+int quote_path_fully = 1;
+
 /* Help to copy the thing properly quoted for the shell safety.
  * any single quote is replaced with '\'', any exclamation point
  * is replaced with '\!', and the whole thing is enclosed in a

shell.c

@@ -3,6 +3,14 @@
 #include "exec_cmd.h"
 #include "strbuf.h"
 
+/* Stubs for functions that make no sense for git-shell. These stubs
+ * are provided here to avoid linking in external redundant modules.
+ */
+void release_pack_memory(size_t need, int fd){}
+void trace_argv_printf(const char **argv, const char *fmt, ...){}
+void trace_printf(const char *fmt, ...){}
+
+
 static int do_generic_cmd(const char *me, char *arg)
 {
 	const char *my_argv[4];