Merge branch 'jj/icase-directory'

* jj/icase-directory:
  Support case folding in git fast-import when core.ignorecase=true
  Support case folding for git add when core.ignorecase=true
  Add case insensitivity support when using git ls-files
  Add case insensitivity support for directories when using git status
  Case insensitivity support for .gitignore via core.ignorecase
  Add string comparison functions that respect the ignore_case variable.
  Makefile & configure: add a NO_FNMATCH_CASEFOLD flag
  Makefile & configure: add a NO_FNMATCH flag

Conflicts:
	Makefile
	config.mak.in
	configure.ac
	fast-import.c

8 files changed, 242 insertions, 27 deletions

diff --git a/Makefile b/Makefile
index 1d42413465..29ebe70599 100644
--- a/Makefile
+++ b/Makefile
@@ -70,6 +70,11 @@ all::
 #
 # Define NO_STRTOK_R if you don't have strtok_r in the C library.
 #
+# Define NO_FNMATCH if you don't have fnmatch in the C library.
+#
+# Define NO_FNMATCH_CASEFOLD if your fnmatch function doesn't have the
+# FNM_CASEFOLD GNU extension.
+#
 # Define NO_LIBGEN_H if you don't have libgen.h.
 #
 # Define NEEDS_LIBGEN if your libgen needs -lgen when linking
@@ -849,6 +854,7 @@ ifeq ($(uname_S),SunOS)
 	NO_MKDTEMP = YesPlease
 	NO_MKSTEMPS = YesPlease
 	NO_REGEX = YesPlease
+	NO_FNMATCH_CASEFOLD = YesPlease
 	ifeq ($(uname_R),5.6)
 		SOCKLEN_T = int
 		NO_HSTRERROR = YesPlease
@@ -1055,6 +1061,7 @@ ifeq ($(uname_S),Windows)
 	NO_STRCASESTR = YesPlease
 	NO_STRLCPY = YesPlease
 	NO_STRTOK_R = YesPlease
+	NO_FNMATCH = YesPlease
 	NO_MEMMEM = YesPlease
 	# NEEDS_LIBICONV = YesPlease
 	NO_ICONV = YesPlease
@@ -1084,8 +1091,8 @@ ifeq ($(uname_S),Windows)
 	AR = compat/vcbuild/scripts/lib.pl
 	CFLAGS =
 	BASIC_CFLAGS = -nologo -I. -I../zlib -Icompat/vcbuild -Icompat/vcbuild/include -DWIN32 -D_CONSOLE -DHAVE_STRING_H -D_CRT_SECURE_NO_WARNINGS -D_CRT_NONSTDC_NO_DEPRECATE
-	COMPAT_OBJS = compat/msvc.o compat/fnmatch/fnmatch.o compat/winansi.o compat/win32/pthread.o compat/win32/syslog.o compat/win32/sys/poll.o
-	COMPAT_CFLAGS = -D__USE_MINGW_ACCESS -DNOGDI -DHAVE_STRING_H -DHAVE_ALLOCA_H -Icompat -Icompat/fnmatch -Icompat/regex -Icompat/fnmatch -Icompat/win32 -DSTRIP_EXTENSION=\".exe\"
+	COMPAT_OBJS = compat/msvc.o compat/winansi.o compat/win32/pthread.o compat/win32/syslog.o compat/win32/sys/poll.o
+	COMPAT_CFLAGS = -D__USE_MINGW_ACCESS -DNOGDI -DHAVE_STRING_H -DHAVE_ALLOCA_H -Icompat -Icompat/regex -Icompat/win32 -DSTRIP_EXTENSION=\".exe\"
 	BASIC_LDFLAGS = -IGNORE:4217 -IGNORE:4049 -NOLOGO -SUBSYSTEM:CONSOLE -NODEFAULTLIB:MSVCRT.lib
 	EXTLIBS = advapi32.lib shell32.lib wininet.lib ws2_32.lib
 	PTHREAD_LIBS =
@@ -1129,6 +1136,7 @@ ifneq (,$(findstring MINGW,$(uname_S)))
 	NO_STRCASESTR = YesPlease
 	NO_STRLCPY = YesPlease
 	NO_STRTOK_R = YesPlease
+	NO_FNMATCH = YesPlease
 	NO_MEMMEM = YesPlease
 	NEEDS_LIBICONV = YesPlease
 	OLD_ICONV = YesPlease
@@ -1152,9 +1160,9 @@ ifneq (,$(findstring MINGW,$(uname_S)))
 	NO_INET_PTON = YesPlease
 	NO_INET_NTOP = YesPlease
 	NO_POSIX_GOODIES = UnfortunatelyYes
-	COMPAT_CFLAGS += -D__USE_MINGW_ACCESS -DNOGDI -Icompat -Icompat/fnmatch -Icompat/win32
+	COMPAT_CFLAGS += -D__USE_MINGW_ACCESS -DNOGDI -Icompat -Icompat/win32
 	COMPAT_CFLAGS += -DSTRIP_EXTENSION=\".exe\"
-	COMPAT_OBJS += compat/mingw.o compat/fnmatch/fnmatch.o compat/winansi.o \
+	COMPAT_OBJS += compat/mingw.o compat/winansi.o \
 		compat/win32/pthread.o compat/win32/syslog.o \
 		compat/win32/sys/poll.o
 	EXTLIBS += -lws2_32
@@ -1364,6 +1372,17 @@ ifdef NO_STRTOK_R
 	COMPAT_CFLAGS += -DNO_STRTOK_R
 	COMPAT_OBJS += compat/strtok_r.o
 endif
+ifdef NO_FNMATCH
+	COMPAT_CFLAGS += -Icompat/fnmatch
+	COMPAT_CFLAGS += -DNO_FNMATCH
+	COMPAT_OBJS += compat/fnmatch/fnmatch.o
+else
+ifdef NO_FNMATCH_CASEFOLD
+	COMPAT_CFLAGS += -Icompat/fnmatch
+	COMPAT_CFLAGS += -DNO_FNMATCH_CASEFOLD
+	COMPAT_OBJS += compat/fnmatch/fnmatch.o
+endif
+endif
 ifdef NO_SETENV
 	COMPAT_CFLAGS += -DNO_SETENV
 	COMPAT_OBJS += compat/setenv.o
diff --git a/config.mak.in b/config.mak.in
index a0c34eec15..56343bab50 100644
--- a/config.mak.in
+++ b/config.mak.in
@@ -47,6 +47,8 @@ NO_C99_FORMAT=@NO_C99_FORMAT@
 NO_HSTRERROR=@NO_HSTRERROR@
 NO_STRCASESTR=@NO_STRCASESTR@
 NO_STRTOK_R=@NO_STRTOK_R@
+NO_FNMATCH=@NO_FNMATCH@
+NO_FNMATCH_CASEFOLD=@NO_FNMATCH_CASEFOLD@
 NO_MEMMEM=@NO_MEMMEM@
 NO_STRLCPY=@NO_STRLCPY@
 NO_UINTMAX_T=@NO_UINTMAX_T@
diff --git a/configure.ac b/configure.ac
index c5bc9a05f3..33dd46262b 100644
--- a/configure.ac
+++ b/configure.ac
@@ -830,6 +830,34 @@ GIT_CHECK_FUNC(strtok_r,
 [NO_STRTOK_R=YesPlease])
 AC_SUBST(NO_STRTOK_R)
 #
+# Define NO_FNMATCH if you don't have fnmatch
+GIT_CHECK_FUNC(fnmatch,
+[NO_FNMATCH=],
+[NO_FNMATCH=YesPlease])
+AC_SUBST(NO_FNMATCH)
+#
+# Define NO_FNMATCH_CASEFOLD if your fnmatch function doesn't have the
+# FNM_CASEFOLD GNU extension.
+AC_CACHE_CHECK([whether the fnmatch function supports the FNMATCH_CASEFOLD GNU extension],
+ [ac_cv_c_excellent_fnmatch], [
+AC_EGREP_CPP(yippeeyeswehaveit,
+	AC_LANG_PROGRAM([
+#include <fnmatch.h>
+],
+[#ifdef FNM_CASEFOLD
+yippeeyeswehaveit
+#endif
+]),
+	[ac_cv_c_excellent_fnmatch=yes],
+	[ac_cv_c_excellent_fnmatch=no])
+])
+if test $ac_cv_c_excellent_fnmatch = yes; then
+	NO_FNMATCH_CASEFOLD=
+else
+	NO_FNMATCH_CASEFOLD=YesPlease
+fi
+AC_SUBST(NO_FNMATCH_CASEFOLD)
+#
 # Define NO_MEMMEM if you don't have memmem.
 GIT_CHECK_FUNC(memmem,
 [NO_MEMMEM=],
diff --git a/dir.c b/dir.c
index b2dfb69eb5..852e60f2a8 100644
--- a/dir.c
+++ b/dir.c
@@ -18,6 +18,22 @@ static int read_directory_recursive(struct dir_struct *dir, const char *path, in
 	int check_only, const struct path_simplify *simplify);
 static int get_dtype(struct dirent *de, const char *path, int len);
 
+/* helper string functions with support for the ignore_case flag */
+int strcmp_icase(const char *a, const char *b)
+{
+	return ignore_case ? strcasecmp(a, b) : strcmp(a, b);
+}
+
+int strncmp_icase(const char *a, const char *b, size_t count)
+{
+	return ignore_case ? strncasecmp(a, b, count) : strncmp(a, b, count);
+}
+
+int fnmatch_icase(const char *pattern, const char *string, int flags)
+{
+	return fnmatch(pattern, string, flags | (ignore_case ? FNM_CASEFOLD : 0));
+}
+
 static int common_prefix(const char **pathspec)
 {
 	const char *path, *slash, *next;
@@ -91,16 +107,30 @@ static int match_one(const char *match, const char *name, int namelen)
 	if (!*match)
 		return MATCHED_RECURSIVELY;
 
-	for (;;) {
-		unsigned char c1 = *match;
-		unsigned char c2 = *name;
-		if (c1 == '\0' || is_glob_special(c1))
-			break;
-		if (c1 != c2)
-			return 0;
-		match++;
-		name++;
-		namelen--;
+	if (ignore_case) {
+		for (;;) {
+			unsigned char c1 = tolower(*match);
+			unsigned char c2 = tolower(*name);
+			if (c1 == '\0' || is_glob_special(c1))
+				break;
+			if (c1 != c2)
+				return 0;
+			match++;
+			name++;
+			namelen--;
+		}
+	} else {
+		for (;;) {
+			unsigned char c1 = *match;
+			unsigned char c2 = *name;
+			if (c1 == '\0' || is_glob_special(c1))
+				break;
+			if (c1 != c2)
+				return 0;
+			match++;
+			name++;
+			namelen--;
+		}
 	}
 
 
@@ -109,8 +139,8 @@ static int match_one(const char *match, const char *name, int namelen)
 	 * we need to match by fnmatch
 	 */
 	matchlen = strlen(match);
-	if (strncmp(match, name, matchlen))
-		return !fnmatch(match, name, 0) ? MATCHED_FNMATCH : 0;
+	if (strncmp_icase(match, name, matchlen))
+		return !fnmatch_icase(match, name, 0) ? MATCHED_FNMATCH : 0;
 
 	if (namelen == matchlen)
 		return MATCHED_EXACTLY;
@@ -375,14 +405,14 @@ int excluded_from_list(const char *pathname,
 			if (x->flags & EXC_FLAG_NODIR) {
 				/* match basename */
 				if (x->flags & EXC_FLAG_NOWILDCARD) {
-					if (!strcmp(exclude, basename))
+					if (!strcmp_icase(exclude, basename))
 						return to_exclude;
 				} else if (x->flags & EXC_FLAG_ENDSWITH) {
 					if (x->patternlen - 1 <= pathlen &&
-					    !strcmp(exclude + 1, pathname + pathlen - x->patternlen + 1))
+					    !strcmp_icase(exclude + 1, pathname + pathlen - x->patternlen + 1))
 						return to_exclude;
 				} else {
-					if (fnmatch(exclude, basename, 0) == 0)
+					if (fnmatch_icase(exclude, basename, 0) == 0)
 						return to_exclude;
 				}
 			}
@@ -397,14 +427,14 @@ int excluded_from_list(const char *pathname,
 
 				if (pathlen < baselen ||
 				    (baselen && pathname[baselen-1] != '/') ||
-				    strncmp(pathname, x->base, baselen))
+				    strncmp_icase(pathname, x->base, baselen))
 				    continue;
 
 				if (x->flags & EXC_FLAG_NOWILDCARD) {
-					if (!strcmp(exclude, pathname + baselen))
+					if (!strcmp_icase(exclude, pathname + baselen))
 						return to_exclude;
 				} else {
-					if (fnmatch(exclude, pathname+baselen,
+					if (fnmatch_icase(exclude, pathname+baselen,
 						    FNM_PATHNAME) == 0)
 					    return to_exclude;
 				}
@@ -470,6 +500,39 @@ enum exist_status {
 };
 
 /*
+ * Do not use the alphabetically stored index to look up
+ * the directory name; instead, use the case insensitive
+ * name hash.
+ */
+static enum exist_status directory_exists_in_index_icase(const char *dirname, int len)
+{
+	struct cache_entry *ce = index_name_exists(&the_index, dirname, len + 1, ignore_case);
+	unsigned char endchar;
+
+	if (!ce)
+		return index_nonexistent;
+	endchar = ce->name[len];
+
+	/*
+	 * The cache_entry structure returned will contain this dirname
+	 * and possibly additional path components.
+	 */
+	if (endchar == '/')
+		return index_directory;
+
+	/*
+	 * If there are no additional path components, then this cache_entry
+	 * represents a submodule.  Submodules, despite being directories,
+	 * are stored in the cache without a closing slash.
+	 */
+	if (!endchar && S_ISGITLINK(ce->ce_mode))
+		return index_gitdir;
+
+	/* This should never be hit, but it exists just in case. */
+	return index_nonexistent;
+}
+
+/*
  * The index sorts alphabetically by entry name, which
  * means that a gitlink sorts as '\0' at the end, while
  * a directory (which is defined not as an entry, but as
@@ -478,7 +541,12 @@ enum exist_status {
  */
 static enum exist_status directory_exists_in_index(const char *dirname, int len)
 {
-	int pos = cache_name_pos(dirname, len);
+	int pos;
+
+	if (ignore_case)
+		return directory_exists_in_index_icase(dirname, len);
+
+	pos = cache_name_pos(dirname, len);
 	if (pos < 0)
 		pos = -pos-1;
 	while (pos < active_nr) {
diff --git a/dir.h b/dir.h
index 278d84cdf7..b3e2104b9f 100644
--- a/dir.h
+++ b/dir.h
@@ -101,4 +101,8 @@ extern int remove_dir_recursively(struct strbuf *path, int flag);
 /* tries to remove the path with empty directories along it, ignores ENOENT */
 extern int remove_path(const char *path);
 
+extern int strcmp_icase(const char *a, const char *b);
+extern int strncmp_icase(const char *a, const char *b, size_t count);
+extern int fnmatch_icase(const char *pattern, const char *string, int flags);
+
 #endif
diff --git a/fast-import.c b/fast-import.c
index 8263dbe841..534c68db6f 100644
--- a/fast-import.c
+++ b/fast-import.c
@@ -156,6 +156,7 @@ Format of STDIN stream:
 #include "csum-file.h"
 #include "quote.h"
 #include "exec_cmd.h"
+#include "dir.h"
 
 #define PACK_ID_BITS 16
 #define MAX_PACK_ID ((1<<PACK_ID_BITS)-1)
@@ -1478,7 +1479,7 @@ static int tree_content_set(
 	t = root->tree;
 	for (i = 0; i < t->entry_count; i++) {
 		e = t->entries[i];
-		if (e->name->str_len == n && !strncmp(p, e->name->str_dat, n)) {
+		if (e->name->str_len == n && !strncmp_icase(p, e->name->str_dat, n)) {
 			if (!slash1) {
 				if (!S_ISDIR(mode)
 						&& e->versions[1].mode == mode
@@ -1547,7 +1548,7 @@ static int tree_content_remove(
 	t = root->tree;
 	for (i = 0; i < t->entry_count; i++) {
 		e = t->entries[i];
-		if (e->name->str_len == n && !strncmp(p, e->name->str_dat, n)) {
+		if (e->name->str_len == n && !strncmp_icase(p, e->name->str_dat, n)) {
 			if (slash1 && !S_ISDIR(e->versions[1].mode))
 				/*
 				 * If p names a file in some subdirectory, and a
@@ -1608,7 +1609,7 @@ static int tree_content_get(
 	t = root->tree;
 	for (i = 0; i < t->entry_count; i++) {
 		e = t->entries[i];
-		if (e->name->str_len == n && !strncmp(p, e->name->str_dat, n)) {
+		if (e->name->str_len == n && !strncmp_icase(p, e->name->str_dat, n)) {
 			if (!slash1) {
 				memcpy(leaf, e, sizeof(*leaf));
 				if (e->tree && is_null_sha1(e->versions[1].sha1))
diff --git a/name-hash.c b/name-hash.c
index 0031d78e8c..c6b6a3fe4c 100644
--- a/name-hash.c
+++ b/name-hash.c
@@ -32,6 +32,42 @@ static unsigned int hash_name(const char *name, int namelen)
 	return hash;
 }
 
+static void hash_index_entry_directories(struct index_state *istate, struct cache_entry *ce)
+{
+	/*
+	 * Throw each directory component in the hash for quick lookup
+	 * during a git status. Directory components are stored with their
+	 * closing slash.  Despite submodules being a directory, they never
+	 * reach this point, because they are stored without a closing slash
+	 * in the cache.
+	 *
+	 * Note that the cache_entry stored with the directory does not
+	 * represent the directory itself.  It is a pointer to an existing
+	 * filename, and its only purpose is to represent existence of the
+	 * directory in the cache.  It is very possible multiple directory
+	 * hash entries may point to the same cache_entry.
+	 */
+	unsigned int hash;
+	void **pos;
+
+	const char *ptr = ce->name;
+	while (*ptr) {
+		while (*ptr && *ptr != '/')
+			++ptr;
+		if (*ptr == '/') {
+			++ptr;
+			hash = hash_name(ce->name, ptr - ce->name);
+			if (!lookup_hash(hash, &istate->name_hash)) {
+				pos = insert_hash(hash, ce, &istate->name_hash);
+				if (pos) {
+					ce->next = *pos;
+					*pos = ce;
+				}
+			}
+		}
+	}
+}
+
 static void hash_index_entry(struct index_state *istate, struct cache_entry *ce)
 {
 	void **pos;
@@ -47,6 +83,9 @@ static void hash_index_entry(struct index_state *istate, struct cache_entry *ce)
 		ce->next = *pos;
 		*pos = ce;
 	}
+
+	if (ignore_case)
+		hash_index_entry_directories(istate, ce);
 }
 
 static void lazy_init_name_hash(struct index_state *istate)
@@ -97,7 +136,21 @@ static int same_name(const struct cache_entry *ce, const char *name, int namelen
 	if (len == namelen && !cache_name_compare(name, namelen, ce->name, len))
 		return 1;
 
-	return icase && slow_same_name(name, namelen, ce->name, len);
+	if (!icase)
+		return 0;
+
+	/*
+	 * If the entry we're comparing is a filename (no trailing slash), then compare
+	 * the lengths exactly.
+	 */
+	if (name[namelen - 1] != '/')
+		return slow_same_name(name, namelen, ce->name, len);
+
+	/*
+	 * For a directory, we point to an arbitrary cache_entry filename.  Just
+	 * make sure the directory portion matches.
+	 */
+	return slow_same_name(name, namelen, ce->name, namelen < len ? namelen : len);
 }
 
 struct cache_entry *index_name_exists(struct index_state *istate, const char *name, int namelen, int icase)
@@ -115,5 +168,22 @@ struct cache_entry *index_name_exists(struct index_state *istate, const char *na
 		}
 		ce = ce->next;
 	}
+
+	/*
+	 * Might be a submodule.  Despite submodules being directories,
+	 * they are stored in the name hash without a closing slash.
+	 * When ignore_case is 1, directories are stored in the name hash
+	 * with their closing slash.
+	 *
+	 * The side effect of this storage technique is we have need to
+	 * remove the slash from name and perform the lookup again without
+	 * the slash.  If a match is made, S_ISGITLINK(ce->mode) will be
+	 * true.
+	 */
+	if (icase && name[namelen - 1] == '/') {
+		ce = index_name_exists(istate, name, namelen - 1, icase);
+		if (ce && S_ISGITLINK(ce->ce_mode))
+			return ce;
+	}
 	return NULL;
 }
diff --git a/read-cache.c b/read-cache.c
index 1f42473e80..4f2e890b01 100644
--- a/read-cache.c
+++ b/read-cache.c
@@ -608,6 +608,29 @@ int add_to_index(struct index_state *istate, const char *path, struct stat *st,
 		ce->ce_mode = ce_mode_from_stat(ent, st_mode);
 	}
 
+	/* When core.ignorecase=true, determine if a directory of the same name but differing
+	 * case already exists within the Git repository.  If it does, ensure the directory
+	 * case of the file being added to the repository matches (is folded into) the existing
+	 * entry's directory case.
+	 */
+	if (ignore_case) {
+		const char *startPtr = ce->name;
+		const char *ptr = startPtr;
+		while (*ptr) {
+			while (*ptr && *ptr != '/')
+				++ptr;
+			if (*ptr == '/') {
+				struct cache_entry *foundce;
+				++ptr;
+				foundce = index_name_exists(&the_index, ce->name, ptr - ce->name, ignore_case);
+				if (foundce) {
+					memcpy((void *)startPtr, foundce->name + (startPtr - ce->name), ptr - startPtr);
+					startPtr = ptr;
+				}
+			}
+		}
+	}
+
 	alias = index_name_exists(istate, ce->name, ce_namelen(ce), ignore_case);
 	if (alias && !ce_stage(alias) && !ie_match_stat(istate, alias, st, ce_option)) {
 		/* Nothing changed, really */