fix gdImageStringFT() fails for empty strings

  https://github.com/libgd/libgd/issues/615

2 files changed, 198 insertions, 2 deletions

diff --git a/gd-bug615.patch b/gd-bug615.patch
new file mode 100644
index 0000000..74192e8
--- /dev/null
+++ b/gd-bug615.patch
@@ -0,0 +1,188 @@
+From 3dd0e308cbd2c24fde2fc9e9b707181252a2de95 Mon Sep 17 00:00:00 2001
+From: "Christoph M. Becker" <cmbecker69@gmx.de>
+Date: Tue, 5 May 2020 12:02:45 +0200
+Subject: [PATCH] Fix #615: gdImageStringFT() fails for empty strings as of
+ libgd 2.3.0 (#633)
+
+We change the return type of `textLayout()` to `ssize_t`, and signal
+failure by returning `-1`, so that laying out an empty string is no
+longer handled as failure.  We make sure that no overflow occurs,
+assuming that all `int` values can be fully represented as `ssize_t`.
+---
+ src/gdft.c                           | 18 +++++++++---------
+ tests/gdimagestringft/.gitignore     |  1 +
+ tests/gdimagestringft/CMakeLists.txt |  1 +
+ tests/gdimagestringft/Makemodule.am  |  1 +
+ tests/gdimagestringft/bug00615.c     | 25 +++++++++++++++++++++++++
+ 5 files changed, 37 insertions(+), 9 deletions(-)
+ create mode 100644 tests/gdimagestringft/bug00615.c
+
+diff --git a/src/gdft.c b/src/gdft.c
+index b483b383..186eefff 100644
+--- a/src/gdft.c
++++ b/src/gdft.c
+@@ -441,7 +441,7 @@ typedef struct {
+ 	uint32_t cluster;
+ } glyphInfo;
+ 
+-static size_t
++static ssize_t
+ textLayout(uint32_t *text, int len,
+ 		FT_Face face, gdFTStringExtraPtr strex,
+ 		glyphInfo **glyph_info)
+@@ -459,19 +459,19 @@ textLayout(uint32_t *text, int len,
+ 		!raqm_set_par_direction (rq, RAQM_DIRECTION_DEFAULT) ||
+ 		!raqm_layout (rq)) {
+ 		raqm_destroy (rq);
+-		return 0;
++		return -1;
+ 	}
+ 
+ 	glyphs = raqm_get_glyphs (rq, &count);
+ 	if (!glyphs) {
+ 		raqm_destroy (rq);
+-		return 0;
++		return -1;
+ 	}
+ 
+ 	info = (glyphInfo*) gdMalloc (sizeof (glyphInfo) * count);
+ 	if (!info) {
+ 		raqm_destroy (rq);
+-		return 0;
++		return -1;
+ 	}
+ 
+ 	for (i = 0; i < count; i++) {
+@@ -489,7 +489,7 @@ textLayout(uint32_t *text, int len,
+ 	FT_Error err;
+ 	info = (glyphInfo*) gdMalloc (sizeof (glyphInfo) * len);
+ 	if (!info) {
+-		return 0;
++		return -1;
+ 	}
+ 	for (count = 0; count < len; count++) {
+ 		/* Convert character code to glyph index */
+@@ -508,7 +508,7 @@ textLayout(uint32_t *text, int len,
+ 		err = FT_Load_Glyph (face, glyph_index, FT_LOAD_DEFAULT);
+ 		if (err) {
+ 			gdFree (info);
+-			return 0;
++			return -1;
+ 		}
+ 		info[count].index = glyph_index;
+ 		info[count].x_offset = 0;
+@@ -527,7 +527,7 @@ textLayout(uint32_t *text, int len,
+ #endif
+ 
+ 	*glyph_info = info;
+-	return count;
++	return count <= SSIZE_MAX ? count : -1;
+ }
+ 
+ /********************************************************************/
+@@ -1108,7 +1108,7 @@ BGD_DECLARE(char *) gdImageStringFTEx (gdImage * im, int *brect, int fg, const c
+ 	char *tmpstr = 0;
+ 	uint32_t *text;
+ 	glyphInfo *info = NULL;
+-	size_t count;
++	ssize_t count;
+ 	int render = (im && (im->trueColor || (fg <= 255 && fg >= -255)));
+ 	FT_BitmapGlyph bm;
+ 	/* 2.0.13: Bob Ostermann: don't force autohint, that's just for testing
+@@ -1409,7 +1409,7 @@ BGD_DECLARE(char *) gdImageStringFTEx (gdImage * im, int *brect, int fg, const c
+ 
+ 	count = textLayout (text , i, face, strex, &info);
+ 
+-	if (!count) {
++	if (count < 0) {
+ 		gdFree (text);
+ 		gdFree (tmpstr);
+ 		gdCacheDelete (tc_cache);
+diff --git a/tests/gdimagestringft/CMakeLists.txt b/tests/gdimagestringft/CMakeLists.txt
+index f46b9006..42868a27 100644
+--- a/tests/gdimagestringft/CMakeLists.txt
++++ b/tests/gdimagestringft/CMakeLists.txt
+@@ -1,5 +1,6 @@
+ IF(FREETYPE_FOUND)
+ LIST(APPEND TESTS_FILES
++	bug00615
+ 	gdimagestringft_bbox
+ )
+ ENDIF(FREETYPE_FOUND)
+diff --git a/tests/gdimagestringft/Makemodule.am b/tests/gdimagestringft/Makemodule.am
+index 0dfe26fb..a62081f4 100644
+--- a/tests/gdimagestringft/Makemodule.am
++++ b/tests/gdimagestringft/Makemodule.am
+@@ -1,5 +1,6 @@
+ if HAVE_LIBFREETYPE
+ libgd_test_programs += \
++	gdimagestringft/bug00615 \
+ 	gdimagestringft/gdimagestringft_bbox
+ endif
+ 
+diff --git a/tests/gdimagestringft/bug00615.c b/tests/gdimagestringft/bug00615.c
+new file mode 100644
+index 00000000..0da51dae
+--- /dev/null
++++ b/tests/gdimagestringft/bug00615.c
+@@ -0,0 +1,25 @@
++/**
++ * Test that rendering an empty string does not fail
++ *
++ * Rendering an empty string with gdImageStringFT() is not supposed to fail;
++ * it is just a no-op.
++ *
++ * See <https://github.com/libgd/libgd/issues/615>
++ */
++
++#include "gd.h"
++#include "gdtest.h"
++
++int main()
++{
++    gdImagePtr im = gdImageCreate(100, 100);
++
++    int rect[8];
++    int fg = gdImageColorAllocate(im, 255, 255, 255);
++    char *path = gdTestFilePath("freetype/DejaVuSans.ttf");
++    char *res = gdImageStringFT(im, rect, fg, path, 12, 0, 10, 10, "");
++
++    gdTestAssert(res == NULL);
++
++    return gdNumFailures();
++}
+From 0be6aec0fe11dce8b8a5674eea5ee23bc700042e Mon Sep 17 00:00:00 2001
+From: Remi Collet <remi@remirepo.net>
+Date: Wed, 15 Jul 2020 08:56:08 +0200
+Subject: [PATCH] Fix #615 using libraqm and avoid unneeded free
+
+---
+ src/gdft.c | 8 +++++++-
+ 1 file changed, 7 insertions(+), 1 deletion(-)
+
+diff --git a/src/gdft.c b/src/gdft.c
+index 186eefff..7eb97077 100644
+--- a/src/gdft.c
++++ b/src/gdft.c
+@@ -449,6 +449,10 @@ textLayout(uint32_t *text, int len,
+ 	size_t count;
+ 	glyphInfo *info;
+ 
++	if (!len) {
++		return 0;
++	}
++
+ #ifdef HAVE_LIBRAQM
+ 	size_t i;
+ 	raqm_glyph_t *glyphs;
+@@ -1566,7 +1570,9 @@ BGD_DECLARE(char *) gdImageStringFTEx (gdImage * im, int *brect, int fg, const c
+ 	}
+ 
+ 	gdFree(text);
+-	gdFree(info);
++	if (info) {
++		gdFree(info);
++	}
+ 
+ 	/* Save the (unkerned) advance from the last character in the xshow vector */
+ 	if (strex && (strex->flags & gdFTEX_XSHOW) && strex->xshow) {
diff --git a/gd.spec b/gd.spec
index 9ab9c57..fc66ff4 100644
--- a/gd.spec
+++ b/gd.spec
@@ -37,7 +37,7 @@ Name:          gd
 Name:          gd-last
 %endif
 Version:       2.3.0
-Release:       1%{?prever}%{?short}%{?dist}
+Release:       2%{?prever}%{?short}%{?dist}
 License:       MIT
 URL:           http://libgd.github.io/
 %if 0%{?commit:1}
@@ -50,6 +50,8 @@ Source0:       https://github.com/libgd/libgd/releases/download/gd-%{version}/li
 # Missing, temporary workaround, fixed upstream for next version
 Source1:       https://raw.githubusercontent.com/libgd/libgd/gd-%{version}/config/getlib.sh
 
+Patch0:        gd-bug615.patch
+
 BuildRequires: freetype-devel
 BuildRequires: fontconfig-devel
 BuildRequires: gettext-devel
@@ -76,6 +78,7 @@ BuildRequires: pkgconfig
 BuildRequires: libtool
 BuildRequires: perl
 BuildRequires: perl-generators
+BuildRequires: perl(FindBin)
 # for fontconfig/basic test
 BuildRequires: liberation-sans-fonts
 %if 0%{?fedora} >= 29
@@ -147,6 +150,7 @@ files for gd, a graphics library for creating PNG and JPEG graphics.
 
 %prep
 %setup -q -n libgd-%{version}%{?prever:-%{prever}}
+%patch0 -p1
 install -m 0755 %{SOURCE1} config/
 
 : $(perl config/getver.pl)
@@ -218,7 +222,7 @@ XFAIL_TESTS="freetype/bug00132 $XFAIL_TESTS"
 export XFAIL_TESTS
 
 : Upstream test suite
-make check
+make check %{?_smp_mflags}
 
 : Check content of pkgconfig
 grep %{version} $RPM_BUILD_ROOT%{_libdir}/pkgconfig/gdlib.pc
@@ -245,6 +249,10 @@ grep %{version} $RPM_BUILD_ROOT%{_libdir}/pkgconfig/gdlib.pc
 
 
 %changelog
+* Wed Jul 15 2020 Remi Collet <remi@remirepo.net> - 2.3.0-2
+- fix gdImageStringFT() fails for empty strings
+  https://github.com/libgd/libgd/issues/615
+
 * Tue Mar 24 2020 Remi Collet <remi@remirepo.net> - 2.3.0-1
 - update to 2.3.0
 - add dependency on libraqm