cleanup: replace membuffer by membufferpp in C-code

Thus, the membuffer data is automatically freed when going
out of scope - one thing less to worry about.

This fixes one use-after-free bug in uploadDiveLogsDE.cpp
and one extremely questionable practice in divetooltipitem.cpp:
The membuffer was a shared instance across all instances
of the DiveToolTipItem.

Remves unnecessary #include directives in files that didn't
even use membuffer.

Signed-off-by: Berthold Stoeger <bstoeger@mail.tuwien.ac.at>

backend-shared/exportfuncs.cpp

@@ -65,7 +65,7 @@ void export_TeX(const char *filename, bool selected_only, bool plain, ExportCall
 	int i;
 	bool need_pagebreak = false;
 
-	struct membuffer buf = {};
+	struct membufferpp buf;
 
 	if (plain) {
 		ssrf = "";
@@ -253,7 +253,6 @@ void export_TeX(const char *filename, bool selected_only, bool plain, ExportCall
 		flush_buffer(&buf, f); /*check for writing errors? */
 		fclose(f);
 	}
-	free_buffer(&buf);
 	cb.setProgress(1000);
 }
 
@@ -265,7 +264,7 @@ void export_depths(const char *filename, bool selected_only)
 	int i;
 	const char *unit = NULL;
 
-	struct membuffer buf = {};
+	struct membufferpp buf;
 
 	for_each_dive (i, dive) {
 		if (selected_only && !dive->selected)
@@ -291,7 +290,6 @@ void export_depths(const char *filename, bool selected_only)
 		flush_buffer(&buf, f); /*check for writing errors? */
 		fclose(f);
 	}
-	free_buffer(&buf);
 }
 #endif /* ! SUBSURFACE_MOBILE */
 

core/divesitehelpers.cpp

@@ -9,7 +9,6 @@
 #include "errorhelper.h"
 #include "subsurface-string.h"
 #include "qthelper.h"
-#include "membuffer.h"
 #include <QDebug>
 #include <QJsonDocument>
 #include <QJsonArray>

core/qthelper.cpp

@@ -7,7 +7,6 @@
 #include "subsurface-string.h"
 #include "gettextfromc.h"
 #include "statistics.h"
-#include "membuffer.h"
 #include "version.h"
 #include "errorhelper.h"
 #include "planner.h"

core/uploadDiveLogsDE.cpp

@@ -97,7 +97,7 @@ bool uploadDiveLogsDE::prepareDives(const QString &tempfile, bool selected)
 		const char *membuf;
 		xmlDoc *transformed;
 		struct zip_source *s;
-		struct membuffer mb = {};
+		struct membufferpp mb;
 		struct xml_params *params = alloc_xml_params();
 
 		/*
@@ -109,9 +109,7 @@ bool uploadDiveLogsDE::prepareDives(const QString &tempfile, bool selected)
 			continue;
 		}
 
-		/* make sure the buffer is empty and add the dive */
+		/* add the dive */
-		mb.len = 0;
-
 		struct dive_site *ds = dive->dive_site;
 
 		if (ds) {
@@ -140,7 +138,7 @@ bool uploadDiveLogsDE::prepareDives(const QString &tempfile, bool selected)
 			put_format(&mb, "</divelog>\n");
 		}
 		membuf = mb_cstring(&mb);
-		streamsize = strlen(membuf);
+		streamsize = mb.len;
 		/*
 		 * Parse the memory buffer into XML document and
 		 * transform it to divelogs.de format, finally dumping
@@ -156,7 +154,6 @@ bool uploadDiveLogsDE::prepareDives(const QString &tempfile, bool selected)
 			free_xml_params(params);
 			return false;
 		}
-		free_buffer(&mb);
 
 		xml_params_add_int(params, "allcylinders", prefs.display_unused_tanks);
 		transformed = xsltApplyStylesheet(xslt, doc, xml_params_get(params));

core/uploadDiveShare.cpp

@@ -27,10 +27,9 @@ uploadDiveShare::uploadDiveShare():
 void uploadDiveShare::doUpload(bool selected, const QString &uid, bool noPublic)
 {
 	//generate json
-	struct membuffer buf = {};
+	struct membufferpp buf;
 	export_list(&buf, NULL, selected, false);
 	QByteArray json_data(buf.buffer, buf.len);
-	free_buffer(&buf);
 
 	//Request to server
 	QNetworkRequest request;

desktop-widgets/subsurfacewebservices.cpp

@@ -13,7 +13,6 @@
 #include "desktop-widgets/mapwidget.h"
 #include "desktop-widgets/tab-widgets/maintab.h"
 #include "core/selection.h"
-#include "core/membuffer.h"
 #include "core/cloudstorage.h"
 #include "core/subsurface-string.h"
 #include "core/uploadDiveLogsDE.h"

desktop-widgets/tab-widgets/TabDivePhotos.cpp

@@ -128,13 +128,12 @@ void TabDivePhotos::saveSubtitles()
 				// Only videos have non-zero duration
 				if (!duration)
 					continue;
-				struct membuffer b = { 0 };
+				struct membufferpp b;
 				save_subtitles_buffer(&b, current_dive, offset, duration);
-				char *data = detach_cstring(&b);
+				const char *data = mb_cstring(&b);
 				subtitlefile.open(QIODevice::WriteOnly);
 				subtitlefile.write(data, strlen(data));
 				subtitlefile.close();
-				free(data);
 			}
 		}
 	}

mobile-widgets/qmlmanager.cpp

@@ -34,7 +34,6 @@
 #include "core/qt-gui.h"
 #include "core/git-access.h"
 #include "core/cloudstorage.h"
-#include "core/membuffer.h"
 #include "core/downloadfromdcthread.h"
 #include "core/subsurfacestartup.h" // for ignore_bt flag
 #include "core/subsurface-string.h"

profile-widget/divetooltipitem.cpp

@@ -221,7 +221,7 @@ void ToolTipItem::setTimeAxis(DiveCartesianAxis *axis)
 
 void ToolTipItem::refresh(const dive *d, const QPointF &pos, bool inPlanner)
 {
-	static struct membuffer mb = {};
+	struct membufferpp mb;
 
 	if(refreshTime.elapsed() < 40)
 		return;
@@ -232,7 +232,6 @@ void ToolTipItem::refresh(const dive *d, const QPointF &pos, bool inPlanner)
 	lastTime = time;
 	clear();
 
-	mb.len = 0;
 	int idx = get_plot_details_new(d, &pInfo, time, &mb);
 
 	tissues.fill();