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[PATCH] Expand ~ and ~user in core.excludesfile, commit.template

From
Matthieu Moy <matthieu.moy@imag.fr>
Date
Nov 16, 2009, 10:07 UTC
Message-ID
<1258366060-27966-1-git-send-email-Matthieu.Moy@imag.fr>

These config variables are parsed to substitute ~ and ~user with getpw entries.

user_path() refactored into new function expand_user_path(), to allow dynamically allocating the return buffer.

Original patch by Karl Chen, modified by Matthieu Moy.
Signed-off-by: Karl Chen <quarl@quarl.org>
Signed-off-by: Matthieu Moy <Matthieu.Moy@imag.fr>
---
The original thread was here:
http://thread.gmane.org/gmane.comp.version-control.git/93250/focus=94276

My version is made a bit simpler by using strbuf for string manipulation in expand_user_path.

I'm not sure I fully adressed Junio's point here: http://thread.gmane.org/gmane.comp.version-control.git/93250/focus=94276

Show 15 quoted lines
> I do not see any strong reason why the single caller of user_path() has to
> keep using the static allocation.  Would it help to reduce the complexity
> of your expand_user_path() implementation, if we fixed the caller along
> the lines of this patch (untested, but just to illustrate the point)?
> 
> [...]
> --- i/path.c
> +++ w/path.c
> @@ -221,19 +221,22 @@ char *enter_repo(char *path, int strict)
>  		if (PATH_MAX <= len)
>  			return NULL;
>  		if (path[0] == '~') {
> -			if (!user_path(used_path, path, PATH_MAX))
> +			char *newpath = expand_user_path(path);
> [...]

I'm just copying back into the static buffer to let enter_repo() do the same string manipulation as it used to do (concatenate with .git suffixes). I think the whole enter_repo could use strbuf instead of static buffers, but that's a different point (probably made easier by my patch).

 Documentation/config.txt |    4 ++-
 builtin-commit.c         |    2 +-
 cache.h                  |    2 +
 config.c                 |   11 +++++-
 path.c                   |   84 +++++++++++++++++++++++++++------------------
 5 files changed, 66 insertions(+), 37 deletions(-)
diff --git a/Documentation/config.txt b/Documentation/config.txt
index d1e2120..c37b51d 100644
--- a/Documentation/config.txt
+++ b/Documentation/config.txt
@@ -380,7 +380,8 @@ Common unit suffixes of 'k', 'm', or 'g' are supported.
 core.excludesfile::
 	In addition to '.gitignore' (per-directory) and
 	'.git/info/exclude', git looks into this file for patterns
-	of files which are not meant to be tracked.  See
+	of files which are not meant to be tracked.  "~" and "~user"
+	are expanded to the user's home directory.  See
 	linkgit:gitignore[5].
 
 core.editor::
@@ -670,6 +671,7 @@ color.ui::
 
 commit.template::
 	Specify a file to use as the template for new commit messages.
+	"~" and "~user" are expanded to the user's home directory.
 
 diff.autorefreshindex::
 	When using 'git-diff' to compare with work tree
diff --git a/builtin-commit.c b/builtin-commit.c
index d525b89..09d2840 100644
--- a/builtin-commit.c
+++ b/builtin-commit.c
@@ -999,7 +999,7 @@ static int git_commit_config(const char *k, const char *v, void *cb)
 	struct wt_status *s = cb;
 
 	if (!strcmp(k, "commit.template"))
-		return git_config_string(&template_file, k, v);
+		return git_config_pathname(&template_file, k, v);
 
 	return git_status_config(k, v, s);
 }
diff --git a/cache.h b/cache.h
index 71a731d..42f7cd8 100644
--- a/cache.h
+++ b/cache.h
@@ -645,6 +645,7 @@ int set_shared_perm(const char *path, int mode);
 #define adjust_shared_perm(path) set_shared_perm((path), 0)
 int safe_create_leading_directories(char *path);
 int safe_create_leading_directories_const(const char *path);
+extern char *expand_user_path(const char *path);
 char *enter_repo(char *path, int strict);
 static inline int is_absolute_path(const char *path)
 {
@@ -903,6 +904,7 @@ extern unsigned long git_config_ulong(const char *, const char *);
 extern int git_config_bool_or_int(const char *, const char *, int *);
 extern int git_config_bool(const char *, const char *);
 extern int git_config_string(const char **, const char *, const char *);
+extern int git_config_pathname(const char **, const char *, const char *);
 extern int git_config_set(const char *, const char *);
 extern int git_config_set_multivar(const char *, const char *, const char *, int);
 extern int git_config_rename_section(const char *, const char *);
diff --git a/config.c b/config.c
index c644061..0fcc4ce 100644
--- a/config.c
+++ b/config.c
@@ -351,6 +351,15 @@ int git_config_string(const char **dest, const char *var, const char *value)
 	return 0;
 }
 
+int git_config_pathname(const char **dest, const char *var, const char *value) {
+	if (!value)
+		return config_error_nonbool(var);
+	*dest = expand_user_path(value);
+	if (!*dest)
+		die("Failed to expand user dir in: '%s'", value);
+	return 0;
+}
+
 static int git_default_core_config(const char *var, const char *value)
 {
 	/* This needs a better name */
@@ -474,7 +483,7 @@ static int git_default_core_config(const char *var, const char *value)
 		return git_config_string(&editor_program, var, value);
 
 	if (!strcmp(var, "core.excludesfile"))
-		return git_config_string(&excludes_file, var, value);
+		return git_config_pathname(&excludes_file, var, value);
 
 	if (!strcmp(var, "core.whitespace")) {
 		if (!value)
diff --git a/path.c b/path.c
index 047fdb0..009c8e0 100644
--- a/path.c
+++ b/path.c
@@ -11,6 +11,7 @@
  * which is what it's designed for.
  */
 #include "cache.h"
+#include "strbuf.h"
 
 static char bad_path[] = "/bad-path/";
 
@@ -207,43 +208,49 @@ int validate_headref(const char *path)
 	return -1;
 }
 
-static char *user_path(char *buf, char *path, int sz)
+static inline struct passwd *getpw_str(const char *username, size_t len)
 {
+	if (len == 0)
+		return getpwuid(getuid());
+
 	struct passwd *pw;
-	char *slash;
-	int len, baselen;
+	char *username_z = xmalloc(len + 1);
+	memcpy(username_z, username, len);
+	username_z[len] = '\0';
+	pw = getpwnam(username_z);
+	free(username_z);
+	return pw;
+}
 
-	if (!path || path[0] != '~')
-		return NULL;
-	path++;
-	slash = strchr(path, '/');
-	if (path[0] == '/' || !path[0]) {
-		pw = getpwuid(getuid());
-	}
-	else {
-		if (slash) {
-			*slash = 0;
-			pw = getpwnam(path);
-			*slash = '/';
-		}
-		else
-			pw = getpwnam(path);
-	}
-	if (!pw || !pw->pw_dir || sz <= strlen(pw->pw_dir))
-		return NULL;
-	baselen = strlen(pw->pw_dir);
-	memcpy(buf, pw->pw_dir, baselen);
-	while ((1 < baselen) && (buf[baselen-1] == '/')) {
-		buf[baselen-1] = 0;
-		baselen--;
-	}
-	if (slash && slash[1]) {
-		len = strlen(slash);
-		if (sz <= baselen + len)
-			return NULL;
-		memcpy(buf + baselen, slash, len + 1);
+/*
+ * Return a string with ~ and ~user expanded via getpw*.  If buf != NULL, then
+ * it is a newly allocated string. Returns NULL on getpw failure or if
+ * path is NULL.
+ */
+char *expand_user_path(const char *path)
+{
+	struct strbuf user_path = STRBUF_INIT;
+	char * first_slash = strchrnul(path, '/');
+	char * to_copy;
+	if (path == NULL)
+		goto return_null;
+
+	if (path[0] == '~') {
+		const char *username = path + 1;
+		size_t username_len = first_slash - username;
+		struct passwd *pw = getpw_str(username, username_len);
+		if (!pw)
+			goto return_null;
+		strbuf_add(&user_path, pw->pw_dir, strlen(pw->pw_dir));
+		to_copy = first_slash;
+	} else if (path[0] != '/') {
+		to_copy = path;
 	}
-	return buf;
+	strbuf_add(&user_path, to_copy, strlen(to_copy));
+	return strbuf_detach(&user_path, NULL);
+return_null:
+	strbuf_release(&user_path);
+	return NULL;
 }
 
 /*
@@ -291,8 +298,17 @@ char *enter_repo(char *path, int strict)
 		if (PATH_MAX <= len)
 			return NULL;
 		if (path[0] == '~') {
-			if (!user_path(used_path, path, PATH_MAX))
+			char *newpath = expand_user_path(path);
+			if (!newpath || (PATH_MAX - 10 < strlen(newpath))) {
+				if (path != newpath)
+					free(newpath);
 				return NULL;
+			}
+			/* Copy back into the static buffer. A pity
+			   since newpath was not bounded, but other
+			   branches of the if are limited by PATH_MAX
+			   anyway. */
+			strcpy(used_path, newpath); free(newpath);
 			strcpy(validated_path, path);
 			path = used_path;
 		}

-- 
1.6.5.2.152.gbbe9e
Next: Junio C Hamano
Message 1 of 24 in “Expand ~ and ~user in core.excludesfile, commit.template”
  1. Expand ~ and ~user in core.excludesfile, commit.templateMatthieu Moy, Nov 16, 2009
  2. Junio C HamanoNov 16, 2009
  3. Junio C HamanoNov 17, 2009
  4. Matthieu MoyNov 17, 2009
  5. Jakub NarebskiNov 16, 2009
  6. Junio C HamanoNov 17, 2009
  7. Matthieu MoyNov 17, 2009
  8. Jakub NarebskiNov 17, 2009
  9. Jakub NarebskiNov 17, 2009
  10. Jeff KingNov 17, 2009
  11. Mike HommeyNov 17, 2009
  12. Andreas SchwabNov 17, 2009
  13. Junio C HamanoNov 17, 2009
  14. Andreas SchwabNov 18, 2009
  15. Matthieu MoyNov 18, 2009
  16. Matthieu MoyNov 17, 2009
  17. Jeff KingNov 17, 2009
  18. Expand ~ and ~user in core.excludesfile, commit.templateMatthieu Moy, Nov 17, 2009
  19. Expand ~ and ~user in core.excludesfile, commit.templateMatthieu Moy, Nov 18, 2009
  20. Expand ~ and ~user in core.excludesfile, commit.templateMatthieu Moy, Nov 18, 2009
  21. expand_user_path: expand ~ to $HOME, not to the actual homedir.Matthieu Moy, Nov 19, 2009
  22. Jeff KingNov 19, 2009
  23. Matthieu MoyNov 19, 2009
  24. Junio C HamanoNov 19, 2009

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