[PATCH] config: support values longer than 1024 bytes

[Erik Faye-Lund <kusmabite@gmail.com>]

parse_value in config.c has a static buffer of 1024 bytes that it
parse the value into. This can sometimes be a problem when a
config file contains very long values.

It's particularly amusing that git-config already is able to write
such files, so it should probably be able to read them as well.

Fix this by using a strbuf instead of a static buffer.

Signed-off-by: Erik Faye-Lund <kusmabite@gmail.com>
---

Here's a proper-ish submission with a commit message and all.

The rather awkward return statement with strdup("") is because
strbuf_detach returns NULL when there's nothing allocated. Even
worse, it returns an uninitialized string if the string has been
initialized with a non-zero 'hint'.

Perhaps I should change it to return a heap-allocated, empty
string in those cases instead of working around it here?

 config.c                |   26 ++++++++++++++------------
 t/t1303-wacky-config.sh |    2 +-
 2 files changed, 15 insertions(+), 13 deletions(-)

diff --git a/config.c b/config.c
index 0abcada..f882f7c 100644
--- a/config.c
+++ b/config.c
@@ -133,23 +133,22 @@ static int get_next_char(void)
 
 static char *parse_value(void)
 {
-	static char value[1024];
-	int quote = 0, comment = 0, len = 0, space = 0;
+	struct strbuf value = STRBUF_INIT;
+	int quote = 0, comment = 0, space = 0;
 
 	for (;;) {
 		int c = get_next_char();
-		if (len >= sizeof(value) - 1)
-			return NULL;
 		if (c == '\n') {
 			if (quote)
 				return NULL;
-			value[len] = 0;
-			return value;
+			return value.len ?
+			    strbuf_detach(&value, NULL) :
+			    strdup("");
 		}
 		if (comment)
 			continue;
 		if (isspace(c) && !quote) {
-			if (len)
+			if (value.len)
 				space++;
 			continue;
 		}
@@ -160,7 +159,7 @@ static char *parse_value(void)
 			}
 		}
 		for (; space; space--)
-			value[len++] = ' ';
+			strbuf_addch(&value, ' ');
 		if (c == '\\') {
 			c = get_next_char();
 			switch (c) {
@@ -180,16 +179,17 @@ static char *parse_value(void)
 				break;
 			/* Reject unknown escape sequences */
 			default:
+				strbuf_release(&value);
 				return NULL;
 			}
-			value[len++] = c;
+			strbuf_addch(&value, c);
 			continue;
 		}
 		if (c == '"') {
 			quote = 1-quote;
 			continue;
 		}
-		value[len++] = c;
+		strbuf_addch(&value, c);
 	}
 }
 
@@ -200,7 +200,7 @@ static inline int iskeychar(int c)
 
 static int get_value(config_fn_t fn, void *data, char *name, unsigned int len)
 {
-	int c;
+	int c, ret;
 	char *value;
 
 	/* Get the full name */
@@ -226,7 +226,9 @@ static int get_value(config_fn_t fn, void *data, char *name, unsigned int len)
 		if (!value)
 			return -1;
 	}
-	return fn(name, value, data);
+	ret = fn(name, value, data);
+	free(value);
+	return ret;
 }
 
 static int get_extended_base_var(char *name, int baselen, int c)
diff --git a/t/t1303-wacky-config.sh b/t/t1303-wacky-config.sh
index 080117c..46103a1 100755
--- a/t/t1303-wacky-config.sh
+++ b/t/t1303-wacky-config.sh
@@ -44,7 +44,7 @@ LONG_VALUE=$(printf "x%01021dx a" 7)
 test_expect_success 'do not crash on special long config line' '
 	setup &&
 	git config section.key "$LONG_VALUE" &&
-	check section.key "fatal: bad config file line 2 in .git/config"
+	check section.key "$LONG_VALUE"
 '
 
 test_done
-- 
1.7.4.msysgit.0.168.g33778