[PATCH 2/2] http.c: implements the GIT_CURL_DEBUG environment variable

[Elia Pinto <gitter.spiros@gmail.com>]

Implements the GIT_CURL_DEBUG environment variable to allow a greater
degree of detail of GIT_CURL_VERBOSE, in particular the complete
transport header and all the data payload exchanged.
It might be useful if a particular situation could require a more
thorough debugging analysis.

Signed-off-by: Elia Pinto <gitter.spiros@gmail.com>
---
 http.c | 97 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 96 insertions(+), 1 deletion(-)

diff --git a/http.c b/http.c
index dfc53c1..079779d 100644
--- a/http.c
+++ b/http.c
@@ -437,6 +437,97 @@ static void set_curl_keepalive(CURL *c)
 }
 #endif
 
+
+static
+void curl_dump(const char *text,
+	  FILE * stream, unsigned char *ptr, size_t size, char nohex)
+{
+	size_t i;
+	size_t c;
+
+	unsigned int width = 0x10;
+
+	if (nohex)
+		/* without the hex output, we can fit more on screen */
+		width = 0x40;
+
+	fprintf(stream, "%s, %10.10ld bytes (0x%8.8lx)\n",
+		text, (long)size, (long)size);
+
+	for (i = 0; i < size; i += width) {
+
+		fprintf(stream, "%4.4lx: ", (long)i);
+
+		if (!nohex) {
+			/* hex not disabled, show it */
+			for (c = 0; c < width; c++)
+				if (i + c < size)
+					fprintf(stream, "%02x ", ptr[i + c]);
+				else
+					fputs("   ", stream);
+		}
+
+		for (c = 0; (c < width) && (i + c < size); c++) {
+			/* check for 0D0A; if found, skip past and start a new line of output */
+			if (nohex && (i + c + 1 < size) && ptr[i + c] == 0x0D
+			    && ptr[i + c + 1] == 0x0A) {
+				i += (c + 2 - width);
+				break;
+			}
+			fprintf(stream, "%c",
+				(ptr[i + c] >= 0x20)
+				&& (ptr[i + c] < 0x80) ? ptr[i + c] : '.');
+			/* check again for 0D0A, to avoid an extra \n if it's at width */
+			if (nohex && (i + c + 2 < size)
+			    && ptr[i + c + 1] == 0x0D
+			    && ptr[i + c + 2] == 0x0A) {
+				i += (c + 3 - width);
+				break;
+			}
+		}
+		fputc('\n', stream);	/* newline */
+	}
+	fflush(stream);
+}
+
+static
+int curl_trace(CURL * handle, curl_infotype type,
+	     char *data, size_t size, void *userp)
+{
+	const char *text;
+	(void)handle;		/* prevent compiler warning */
+
+	switch (type) {
+	case CURLINFO_TEXT:
+		fprintf(stderr, "== Info: %s", data);
+	default:		/* in case a new one is introduced to shock us */
+		return 0;
+
+	case CURLINFO_HEADER_OUT:
+		text = "=> Send header";
+		break;
+	case CURLINFO_DATA_OUT:
+		text = "=> Send data";
+		break;
+	case CURLINFO_SSL_DATA_OUT:
+		text = "=> Send SSL data";
+		break;
+	case CURLINFO_HEADER_IN:
+		text = "<= Recv header";
+		break;
+	case CURLINFO_DATA_IN:
+		text = "<= Recv data";
+		break;
+	case CURLINFO_SSL_DATA_IN:
+		text = "<= Recv SSL data";
+		break;
+	}
+
+	curl_dump(text, stderr, (unsigned char *)data, size, 1);
+	return 0;
+}
+
+
 static CURL *get_curl_handle(void)
 {
 	CURL *result = curl_easy_init();
@@ -532,7 +623,11 @@ static CURL *get_curl_handle(void)
 			"your curl version is too old (>= 7.19.4)");
 #endif
 
-	if (getenv("GIT_CURL_VERBOSE"))
+	if (getenv("GIT_CURL_DEBUG")) {
+		curl_easy_setopt(result, CURLOPT_VERBOSE, 1);
+		curl_easy_setopt(result, CURLOPT_DEBUGFUNCTION, curl_trace);
+		curl_easy_setopt(result, CURLOPT_DEBUGDATA, NULL);
+	} else if (getenv("GIT_CURL_VERBOSE"))
 		curl_easy_setopt(result, CURLOPT_VERBOSE, 1);
 
 	curl_easy_setopt(result, CURLOPT_USERAGENT,
-- 
2.7.0.416.gbf6b42c.dirty