[PATCH] Make use of stat.ctime configurable

[Alex Riesen <raa.lkml@gmail.com>]

because there are situations where it produces too much false
positives. Like when file system crawlers keep changing it when
scanning and using the ctime for marking scanned files.

The default is to allow use of ctime.

Signed-off-by: Alex Riesen <raa.lkml@gmail.com>
---
Johannes Schindelin, Sat, Jul 26, 2008 02:57:25 +0200:
> On Fri, 25 Jul 2008, Alex Riesen wrote:
> > But, given the fact, that somewhere sometimes its very-very annoying to 
> > have even one (un)changed file, something must be done about it. Maybe 
> > just direct
> > 
> > [...]
> > 	trustctime = false
> 
> ... which is all Junio and I were asking all along: a separate way to ask 
> for ignoring ctime; not just DWIM it on top of the executable bit.

Oh...

 cache.h       |    1 +
 config.c      |    4 ++++
 environment.c |    1 +
 read-cache.c  |    2 +-
 4 files changed, 7 insertions(+), 1 deletions(-)

diff --git a/cache.h b/cache.h
index 38985aa..00d02d3 100644
--- a/cache.h
+++ b/cache.h
@@ -421,6 +421,7 @@ extern int delete_ref(const char *, const unsigned char *sha1);
 
 /* Environment bits from configuration mechanism */
 extern int trust_executable_bit;
+extern int trust_file_ctime;
 extern int quote_path_fully;
 extern int has_symlinks;
 extern int ignore_case;
diff --git a/config.c b/config.c
index 1e066c7..860e8ab 100644
--- a/config.c
+++ b/config.c
@@ -341,6 +341,10 @@ static int git_default_core_config(const char *var, const char *value)
 		trust_executable_bit = git_config_bool(var, value);
 		return 0;
 	}
+	if (!strcmp(var, "core.filectime")) {
+		trust_file_ctime = git_config_bool(var, value);
+		return 0;
+	}
 
 	if (!strcmp(var, "core.quotepath")) {
 		quote_path_fully = git_config_bool(var, value);
diff --git a/environment.c b/environment.c
index 4a88a17..4982771 100644
--- a/environment.c
+++ b/environment.c
@@ -13,6 +13,7 @@ char git_default_email[MAX_GITNAME];
 char git_default_name[MAX_GITNAME];
 int user_ident_explicitly_given;
 int trust_executable_bit = 1;
+int trust_file_ctime = 1;
 int has_symlinks = 1;
 int ignore_case;
 int assume_unchanged;
diff --git a/read-cache.c b/read-cache.c
index a50a851..00d39dc 100644
--- a/read-cache.c
+++ b/read-cache.c
@@ -181,7 +181,7 @@ static int ce_match_stat_basic(struct cache_entry *ce, struct stat *st)
 	}
 	if (ce->ce_mtime != (unsigned int) st->st_mtime)
 		changed |= MTIME_CHANGED;
-	if (ce->ce_ctime != (unsigned int) st->st_ctime)
+	if (trust_file_ctime && ce->ce_ctime != (unsigned int) st->st_ctime)
 		changed |= CTIME_CHANGED;
 
 	if (ce->ce_uid != (unsigned int) st->st_uid ||
-- 
1.6.0.rc0.76.g581e