[PATCH] Refactor 'trust_executable_bit' to repository-scoped setting

[drona <dronarajgyawali@gmail.com>]

From: Dorna Raj Gyawali <dronarajgyawali@gmail.com>

Currently, 'trust_executable_bit' is a global variable in environment.c,
which controls how executable bits are interpreted when creating/updating
cache entries.

This patch moves 'trust_executable_bit' into 'struct repo_settings', making
it a repository-scoped configuration. All references in files have been updated to use
'the_repository->settings.trust_executable_bit'.

Why this is a good candidate:
- It's a self-contained global variable that only affects file mode logic.
- Low risk: changes only impact mode calculations and related apply/update
  operations.
- Makes Git codebase more maintainable and prepares for future multi-repo
  support.

- Manual sanity check with a test repo confirms executable bits behave correctly.

Signed-off-by: Dorna Raj Gyawali <dronarajgyawali@gmail.com>
---
 apply.c                |  4 ++--
 builtin/update-index.c |  2 +-
 diff-lib.c             | 10 +++++-----
 environment.c          |  3 +--
 environment.h          |  1 -
 read-cache.c           | 10 +++++-----
 read-cache.h           | 11 +++++++----
 repo-settings.h        |  6 +++++-
 8 files changed, 26 insertions(+), 21 deletions(-)

diff --git a/apply.c b/apply.c
index d044c95d50..2bcb22a4bc 100644
--- a/apply.c
+++ b/apply.c
@@ -3838,8 +3838,8 @@ static int check_preimage(struct apply_state *state,
 		if (*ce && !(*ce)->ce_mode)
 			BUG("ce_mode == 0 for path '%s'", old_name);
 
-		if (trust_executable_bit || !S_ISREG(st->st_mode))
-			st_mode = ce_mode_from_stat(*ce, st->st_mode);
+		if (the_repository->settings.trust_executable_bit  || !S_ISREG(st->st_mode))
+			st_mode = ce_mode_from_stat(the_repository, *ce, st->st_mode);
 		else if (*ce)
 			st_mode = (*ce)->ce_mode;
 		else
diff --git a/builtin/update-index.c b/builtin/update-index.c
index 8a5907767b..7917bd286f 100644
--- a/builtin/update-index.c
+++ b/builtin/update-index.c
@@ -293,7 +293,7 @@ static int add_one_path(const struct cache_entry *old, const char *path, int len
 	ce->ce_flags = create_ce_flags(0);
 	ce->ce_namelen = len;
 	fill_stat_cache_info(the_repository->index, ce, st);
-	ce->ce_mode = ce_mode_from_stat(old, st->st_mode);
+	ce->ce_mode = ce_mode_from_stat(the_repository, old, st->st_mode);
 
 	if (index_path(the_repository->index, &ce->oid, path, st,
 		       info_only ? 0 : INDEX_WRITE_OBJECT)) {
diff --git a/diff-lib.c b/diff-lib.c
index ae91027a02..894358c8b0 100644
--- a/diff-lib.c
+++ b/diff-lib.c
@@ -160,7 +160,7 @@ void run_diff_files(struct rev_info *revs, unsigned int option)
 
 			changed = check_removed(ce, &st);
 			if (!changed)
-				wt_mode = ce_mode_from_stat(ce, st.st_mode);
+				wt_mode = ce_mode_from_stat(the_repository, ce, st.st_mode);
 			else {
 				if (changed < 0) {
 					perror(ce->name);
@@ -193,7 +193,7 @@ void run_diff_files(struct rev_info *revs, unsigned int option)
 					num_compare_stages++;
 					oidcpy(&dpath->parent[stage - 2].oid,
 					       &nce->oid);
-					dpath->parent[stage-2].mode = ce_mode_from_stat(nce, mode);
+					dpath->parent[stage-2].mode = ce_mode_from_stat(the_repository,nce, mode);
 					dpath->parent[stage-2].status =
 						DIFF_STATUS_MODIFIED;
 				}
@@ -262,7 +262,7 @@ void run_diff_files(struct rev_info *revs, unsigned int option)
 				continue;
 			} else if (revs->diffopt.ita_invisible_in_index &&
 				   ce_intent_to_add(ce)) {
-				newmode = ce_mode_from_stat(ce, st.st_mode);
+				newmode = ce_mode_from_stat(the_repository, ce, st.st_mode);
 				diff_addremove(&revs->diffopt, '+', newmode,
 					       null_oid(the_hash_algo), 0, ce->name, 0);
 				continue;
@@ -270,7 +270,7 @@ void run_diff_files(struct rev_info *revs, unsigned int option)
 
 			changed = match_stat_with_submodule(&revs->diffopt, ce, &st,
 							    ce_option, &dirty_submodule);
-			newmode = ce_mode_from_stat(ce, st.st_mode);
+			newmode = ce_mode_from_stat(the_repository, ce, st.st_mode);
 		}
 
 		if (!changed && !dirty_submodule) {
@@ -338,7 +338,7 @@ static int get_stat_data(const struct cache_entry *ce,
 		changed = match_stat_with_submodule(diffopt, ce, &st,
 						    0, dirty_submodule);
 		if (changed) {
-			mode = ce_mode_from_stat(ce, st.st_mode);
+			mode = ce_mode_from_stat(the_repository, ce, st.st_mode);
 			oid = null_oid(the_hash_algo);
 		}
 	}
diff --git a/environment.c b/environment.c
index 0026eb2274..861ef084dc 100644
--- a/environment.c
+++ b/environment.c
@@ -41,7 +41,6 @@
 static int pack_compression_seen;
 static int zlib_compression_seen;
 
-int trust_executable_bit = 1;
 int trust_ctime = 1;
 int check_stat = 1;
 int has_symlinks = 1;
@@ -306,7 +305,7 @@ int git_default_core_config(const char *var, const char *value,
 {
 	/* This needs a better name */
 	if (!strcmp(var, "core.filemode")) {
-		trust_executable_bit = git_config_bool(var, value);
+		the_repository->settings.trust_executable_bit = git_config_bool(var, value);
 		return 0;
 	}
 	if (!strcmp(var, "core.trustctime")) {
diff --git a/environment.h b/environment.h
index 27f657af04..7f3437f369 100644
--- a/environment.h
+++ b/environment.h
@@ -144,7 +144,6 @@ int is_bare_repository(void);
 extern char *git_work_tree_cfg;
 
 /* Environment bits from configuration mechanism */
-extern int trust_executable_bit;
 extern int trust_ctime;
 extern int check_stat;
 extern int has_symlinks;
diff --git a/read-cache.c b/read-cache.c
index 0c07c3aef7..b1fcb9e1a0 100644
--- a/read-cache.c
+++ b/read-cache.c
@@ -201,13 +201,13 @@ void fill_stat_cache_info(struct index_state *istate, struct cache_entry *ce, st
 
 static unsigned int st_mode_from_ce(const struct cache_entry *ce)
 {
-	extern int trust_executable_bit, has_symlinks;
+	extern int has_symlinks;
 
 	switch (ce->ce_mode & S_IFMT) {
 	case S_IFLNK:
 		return has_symlinks ? S_IFLNK : (S_IFREG | 0644);
 	case S_IFREG:
-		return (ce->ce_mode & (trust_executable_bit ? 0755 : 0644)) | S_IFREG;
+		return (ce->ce_mode & (the_repository->settings.trust_executable_bit ? 0755 : 0644)) | S_IFREG;
 	case S_IFGITLINK:
 		return S_IFDIR | 0755;
 	case S_IFDIR:
@@ -317,7 +317,7 @@ static int ce_match_stat_basic(const struct cache_entry *ce, struct stat *st)
 		/* We consider only the owner x bit to be relevant for
 		 * "mode changes"
 		 */
-		if (trust_executable_bit &&
+		if (the_repository->settings.trust_executable_bit &&
 		    (0100 & (ce->ce_mode ^ st->st_mode)))
 			changed |= MODE_CHANGED;
 		break;
@@ -738,7 +738,7 @@ int add_to_index(struct index_state *istate, const char *path, struct stat *st,
 		ce->ce_flags |= CE_INTENT_TO_ADD;
 
 
-	if (trust_executable_bit && has_symlinks) {
+	if (the_repository->settings.trust_executable_bit && has_symlinks) {
 		ce->ce_mode = create_ce_mode(st_mode);
 	} else {
 		/* If there is an existing entry, pick the mode bits and type
@@ -748,7 +748,7 @@ int add_to_index(struct index_state *istate, const char *path, struct stat *st,
 		int pos = index_name_pos_also_unmerged(istate, path, namelen);
 
 		ent = (0 <= pos) ? istate->cache[pos] : NULL;
-		ce->ce_mode = ce_mode_from_stat(ent, st_mode);
+		ce->ce_mode = ce_mode_from_stat(the_repository, ent, st_mode);
 	}
 
 	/* When core.ignorecase=true, determine if a directory of the same name but differing
diff --git a/read-cache.h b/read-cache.h
index 043da1f1aa..4e88d476aa 100644
--- a/read-cache.h
+++ b/read-cache.h
@@ -4,15 +4,18 @@
 #include "read-cache-ll.h"
 #include "object.h"
 #include "pathspec.h"
+#include "repository.h"
 
-static inline unsigned int ce_mode_from_stat(const struct cache_entry *ce,
-					     unsigned int mode)
+static inline unsigned int ce_mode_from_stat(
+						struct repository *repo,
+						const struct cache_entry *ce,
+					    unsigned int mode)
 {
-	extern int trust_executable_bit, has_symlinks;
+	extern int has_symlinks;
 	if (!has_symlinks && S_ISREG(mode) &&
 	    ce && S_ISLNK(ce->ce_mode))
 		return ce->ce_mode;
-	if (!trust_executable_bit && S_ISREG(mode)) {
+	if (!repo->settings.trust_executable_bit && S_ISREG(mode)) {
 		if (ce && S_ISREG(ce->ce_mode))
 			return ce->ce_mode;
 		return create_ce_mode(0666);
diff --git a/repo-settings.h b/repo-settings.h
index cad9c3f0cc..a12e763f4f 100644
--- a/repo-settings.h
+++ b/repo-settings.h
@@ -48,7 +48,10 @@ struct repo_settings {
 	 * replace_refs_enabled() for more details.
 	 */
 	int read_replace_refs;
-
+	
+	/* Whether to trust executable bit on filesystem (core.filemode) */
+	int trust_executable_bit;
+	
 	struct fsmonitor_settings *fsmonitor; /* lazily loaded */
 
 	int index_version;
@@ -74,6 +77,7 @@ struct repo_settings {
 #define REPO_SETTINGS_INIT { \
 	.shared_repository = -1, \
 	.index_version = -1, \
+	.trust_executable_bit = 1, \
 	.core_untracked_cache = UNTRACKED_CACHE_KEEP, \
 	.fetch_negotiation_algorithm = FETCH_NEGOTIATION_CONSECUTIVE, \
 	.warn_ambiguous_refs = -1, \
-- 
2.43.0