Merge branch 'bc/maint-diff-hunk-header-fix' into maint

* bc/maint-diff-hunk-header-fix:
  t4018-diff-funcname: test syntax of builtin xfuncname patterns
  diff hunk pattern: fix misconverted "\{" tex macro introducers
  diff: use extended regexp to find hunk headers
  diff.*.xfuncname which uses "extended" regex's for hunk header selection
  diff.c: associate a flag with each pattern and use it for compiling regex
  diff.c: return pattern entry pointer rather than just the hunk header pattern

Conflicts:
	Documentation/gitattributes.txt

5 files changed, 72 insertions, 49 deletions

diff --git a/Documentation/gitattributes.txt b/Documentation/gitattributes.txt
index 89627688b8..53da9b4f6b 100644
--- a/Documentation/gitattributes.txt
+++ b/Documentation/gitattributes.txt
@@ -288,13 +288,13 @@ for paths.
 *.tex	diff=tex
 ------------------------
 
-Then, you would define a "diff.tex.funcname" configuration to
+Then, you would define a "diff.tex.xfuncname" configuration to
 specify a regular expression that matches a line that you would
 want to appear as the hunk header "TEXT", like this:
 
 ------------------------
 [diff "tex"]
-	funcname = "^\\(\\\\\\(sub\\)*section{.*\\)$"
+	xfuncname = "^(\\\\(sub)*section\\{.*)$"
 ------------------------
 
 Note.  A single level of backslashes are eaten by the
diff --git a/diff.c b/diff.c
index 9385a36f1e..781fa15ac1 100644
--- a/diff.c
+++ b/diff.c
@@ -94,32 +94,37 @@ static int parse_lldiff_command(const char *var, const char *ep, const char *val
  * to define a customized regexp to find the beginning of a function to
  * be used for hunk header lines of "diff -p" style output.
  */
-static struct funcname_pattern {
+struct funcname_pattern_entry {
 	char *name;
 	char *pattern;
-	struct funcname_pattern *next;
+	int cflags;
+};
+static struct funcname_pattern_list {
+	struct funcname_pattern_list *next;
+	struct funcname_pattern_entry e;
 } *funcname_pattern_list;
 
-static int parse_funcname_pattern(const char *var, const char *ep, const char *value)
+static int parse_funcname_pattern(const char *var, const char *ep, const char *value, int cflags)
 {
 	const char *name;
 	int namelen;
-	struct funcname_pattern *pp;
+	struct funcname_pattern_list *pp;
 
 	name = var + 5; /* "diff." */
 	namelen = ep - name;
 
 	for (pp = funcname_pattern_list; pp; pp = pp->next)
-		if (!strncmp(pp->name, name, namelen) && !pp->name[namelen])
+		if (!strncmp(pp->e.name, name, namelen) && !pp->e.name[namelen])
 			break;
 	if (!pp) {
 		pp = xcalloc(1, sizeof(*pp));
-		pp->name = xmemdupz(name, namelen);
+		pp->e.name = xmemdupz(name, namelen);
 		pp->next = funcname_pattern_list;
 		funcname_pattern_list = pp;
 	}
-	free(pp->pattern);
-	pp->pattern = xstrdup(value);
+	free(pp->e.pattern);
+	pp->e.pattern = xstrdup(value);
+	pp->e.cflags = cflags;
 	return 0;
 }
 
@@ -182,7 +187,13 @@ int git_diff_basic_config(const char *var, const char *value, void *cb)
 			if (!strcmp(ep, ".funcname")) {
 				if (!value)
 					return config_error_nonbool(var);
-				return parse_funcname_pattern(var, ep, value);
+				return parse_funcname_pattern(var, ep, value,
+					0);
+			} else if (!strcmp(ep, ".xfuncname")) {
+				if (!value)
+					return config_error_nonbool(var);
+				return parse_funcname_pattern(var, ep, value,
+					REG_EXTENDED);
 			}
 		}
 	}
@@ -1377,39 +1388,40 @@ int diff_filespec_is_binary(struct diff_filespec *one)
 	return one->is_binary;
 }
 
-static const char *funcname_pattern(const char *ident)
+static const struct funcname_pattern_entry *funcname_pattern(const char *ident)
 {
-	struct funcname_pattern *pp;
+	struct funcname_pattern_list *pp;
 
 	for (pp = funcname_pattern_list; pp; pp = pp->next)
-		if (!strcmp(ident, pp->name))
-			return pp->pattern;
+		if (!strcmp(ident, pp->e.name))
+			return &pp->e;
 	return NULL;
 }
 
-static struct builtin_funcname_pattern {
-	const char *name;
-	const char *pattern;
-} builtin_funcname_pattern[] = {
-	{ "java", "!^[ 	]*\\(catch\\|do\\|for\\|if\\|instanceof\\|"
-			"new\\|return\\|switch\\|throw\\|while\\)\n"
-			"^[ 	]*\\(\\([ 	]*"
-			"[A-Za-z_][A-Za-z_0-9]*\\)\\{2,\\}"
-			"[ 	]*([^;]*\\)$" },
-	{ "pascal", "^\\(\\(procedure\\|function\\|constructor\\|"
-			"destructor\\|interface\\|implementation\\|"
-			"initialization\\|finalization\\)[ \t]*.*\\)$"
-			"\\|"
-			"^\\(.*=[ \t]*\\(class\\|record\\).*\\)$"
-			},
-	{ "bibtex", "\\(@[a-zA-Z]\\{1,\\}[ \t]*{\\{0,1\\}[ \t]*[^ \t\"@',\\#}{~%]*\\).*$" },
-	{ "tex", "^\\(\\\\\\(\\(sub\\)*section\\|chapter\\|part\\)\\*\\{0,1\\}{.*\\)$" },
-	{ "ruby", "^\\s*\\(\\(class\\|module\\|def\\)\\s.*\\)$" },
+static const struct funcname_pattern_entry builtin_funcname_pattern[] = {
+	{ "java",
+	  "!^[ \t]*(catch|do|for|if|instanceof|new|return|switch|throw|while)\n"
+	  "^[ \t]*(([ \t]*[A-Za-z_][A-Za-z_0-9]*){2,}[ \t]*\\([^;]*)$",
+	  REG_EXTENDED },
+	{ "pascal",
+	  "^((procedure|function|constructor|destructor|interface|"
+		"implementation|initialization|finalization)[ \t]*.*)$"
+	  "|"
+	  "^(.*=[ \t]*(class|record).*)$",
+	  REG_EXTENDED },
+	{ "bibtex", "(@[a-zA-Z]{1,}[ \t]*\\{{0,1}[ \t]*[^ \t\"@',\\#}{~%]*).*$",
+	  REG_EXTENDED },
+	{ "tex",
+	  "^(\\\\((sub)*section|chapter|part)\\*{0,1}\\{.*)$",
+	  REG_EXTENDED },
+	{ "ruby", "^[ \t]*((class|module|def)[ \t].*)$",
+	  REG_EXTENDED },
 };
 
-static const char *diff_funcname_pattern(struct diff_filespec *one)
+static const struct funcname_pattern_entry *diff_funcname_pattern(struct diff_filespec *one)
 {
-	const char *ident, *pattern;
+	const char *ident;
+	const struct funcname_pattern_entry *pe;
 	int i;
 
 	diff_filespec_check_attr(one);
@@ -1424,9 +1436,9 @@ static const char *diff_funcname_pattern(struct diff_filespec *one)
 		return funcname_pattern("default");
 
 	/* Look up custom "funcname.$ident" regexp from config. */
-	pattern = funcname_pattern(ident);
-	if (pattern)
-		return pattern;
+	pe = funcname_pattern(ident);
+	if (pe)
+		return pe;
 
 	/*
 	 * And define built-in fallback patterns here.  Note that
@@ -1434,7 +1446,7 @@ static const char *diff_funcname_pattern(struct diff_filespec *one)
 	 */
 	for (i = 0; i < ARRAY_SIZE(builtin_funcname_pattern); i++)
 		if (!strcmp(ident, builtin_funcname_pattern[i].name))
-			return builtin_funcname_pattern[i].pattern;
+			return &builtin_funcname_pattern[i];
 
 	return NULL;
 }
@@ -1512,11 +1524,11 @@ static void builtin_diff(const char *name_a,
 		xdemitconf_t xecfg;
 		xdemitcb_t ecb;
 		struct emit_callback ecbdata;
-		const char *funcname_pattern;
+		const struct funcname_pattern_entry *pe;
 
-		funcname_pattern = diff_funcname_pattern(one);
-		if (!funcname_pattern)
-			funcname_pattern = diff_funcname_pattern(two);
+		pe = diff_funcname_pattern(one);
+		if (!pe)
+			pe = diff_funcname_pattern(two);
 
 		memset(&xecfg, 0, sizeof(xecfg));
 		memset(&ecbdata, 0, sizeof(ecbdata));
@@ -1528,8 +1540,8 @@ static void builtin_diff(const char *name_a,
 		xpp.flags = XDF_NEED_MINIMAL | o->xdl_opts;
 		xecfg.ctxlen = o->context;
 		xecfg.flags = XDL_EMIT_FUNCNAMES;
-		if (funcname_pattern)
-			xdiff_set_find_func(&xecfg, funcname_pattern);
+		if (pe)
+			xdiff_set_find_func(&xecfg, pe->pattern, pe->cflags);
 		if (!diffopts)
 			;
 		else if (!prefixcmp(diffopts, "--unified="))
diff --git a/t/t4018-diff-funcname.sh b/t/t4018-diff-funcname.sh
index 18bcd9713d..99fff973eb 100755
--- a/t/t4018-diff-funcname.sh
+++ b/t/t4018-diff-funcname.sh
@@ -32,7 +32,18 @@ EOF
 
 sed 's/beer\\/beer,\\/' < Beer.java > Beer-correct.java
 
+builtin_patterns="bibtex java pascal ruby tex"
+for p in $builtin_patterns
+do
+	test_expect_success "builtin $p pattern compiles" '
+		echo "*.java diff=$p" > .gitattributes &&
+		! ( git diff --no-index Beer.java Beer-correct.java 2>&1 |
+			grep "fatal" > /dev/null )
+	'
+done
+
 test_expect_success 'default behaviour' '
+	rm -f .gitattributes &&
 	git diff --no-index Beer.java Beer-correct.java |
 	grep "^@@.*@@ public class Beer"
 '
@@ -58,7 +69,7 @@ test_expect_success 'last regexp must not be negated' '
 '
 
 test_expect_success 'alternation in pattern' '
-	git config diff.java.funcname "^[ 	]*\\(\\(public\\|static\\).*\\)$"
+	git config diff.java.xfuncname "^[ 	]*((public|static).*)$" &&
 	git diff --no-index Beer.java Beer-correct.java |
 	grep "^@@.*@@ public static void main("
 '
diff --git a/xdiff-interface.c b/xdiff-interface.c
index 61dc5c5470..2c81f40cb6 100644
--- a/xdiff-interface.c
+++ b/xdiff-interface.c
@@ -206,7 +206,7 @@ static long ff_regexp(const char *line, long len,
 	return result;
 }
 
-void xdiff_set_find_func(xdemitconf_t *xecfg, const char *value)
+void xdiff_set_find_func(xdemitconf_t *xecfg, const char *value, int cflags)
 {
 	int i;
 	struct ff_regs *regs;
@@ -231,7 +231,7 @@ void xdiff_set_find_func(xdemitconf_t *xecfg, const char *value)
 			expression = buffer = xstrndup(value, ep - value);
 		else
 			expression = value;
-		if (regcomp(&reg->re, expression, 0))
+		if (regcomp(&reg->re, expression, cflags))
 			die("Invalid regexp to look for hunk header: %s", expression);
 		free(buffer);
 		value = ep + 1;
diff --git a/xdiff-interface.h b/xdiff-interface.h
index f7f791d96b..33cab9dd59 100644
--- a/xdiff-interface.h
+++ b/xdiff-interface.h
@@ -21,6 +21,6 @@ int parse_hunk_header(char *line, int len,
 int read_mmfile(mmfile_t *ptr, const char *filename);
 int buffer_is_binary(const char *ptr, unsigned long size);
 
-extern void xdiff_set_find_func(xdemitconf_t *xecfg, const char *line);
+extern void xdiff_set_find_func(xdemitconf_t *xecfg, const char *line, int cflags);
 
 #endif