From 0378bd67e12c9e7602c70f7d64a1216a76bd2e38 Mon Sep 17 00:00:00 2001
From: Mirco Miranda <mircomir@gmail.com>
Date: Thu, 24 Oct 2024 15:07:44 +0000
Subject: [PATCH] TGA: Fixed GrayA image loading error

Gray TGA images with alpha were loading incorrectly and tests did not detect the error since the BW(A).TGA images were actually RGB(A) images.
---
 autotests/read/tga/bw.tga  | Bin 3090 -> 485 bytes
 autotests/read/tga/bwa.tga | Bin 4114 -> 737 bytes
 src/imageformats/tga.cpp   |  27 +++++++++++++++++++--------
 3 files changed, 19 insertions(+), 8 deletions(-)

diff --git a/autotests/read/tga/bw.tga b/autotests/read/tga/bw.tga
index 0ae195a82cb03a65938966091140981f20d258b7..2cd375eab6e7d865ed07faed78f060d7fa282a7f 100644
GIT binary patch
literal 485
zcmZQz;AVgT1qKl0P?-N81e^ae{`u1Qk?Y;_XYby>dhzVhljn^un4Uj<*7$_^`HQ!|
z8vi%_XZ>?~c6)P4V=#M3RZ^6{y=Pcs6j!KEpoeEjOwp-dAQfMxYe<R<HnOt|ig0nV
zGBL9^adNV-GqZ4T2{n9#DUc9t<YN?-Zq(%9XJl8<GcdNYXtZNBHgsM89cD{wb7Q?o
z^Mti49NC1jH}5%o{_M>gNA{k4`w!yK){oquf4nN;VGn!!>-XP3jsKW`|N8x}@qh1s
z*3X@SY(7uALCha(l-Wa{gPFe%8gfFJf6rO6_&kM(9yaEHivHSbz!~)dCQ3l<Zhfw3
zh}s`(HMx^sfwg_^ml3Ic4`MQYY-^NYZ21Ubw*uL%Sl9?Pte+=HL$$L0Sf|CE0x|IS
zaTlTDw_vmXy<OjM>R0#wzW>bszJL7H1CBCiJTim?g}R1$27CJZ=|;GD`nc*b003Yd
B_{snP

literal 3090
zcmeH}&r4!a6vxfX(UOs($f(5wH;s#a(576B1O*9!#8iuP746!kt6GeZ8Lev9qJO|e
z>7r%2h=Nckw@N$Hia=vfP)eKm@MPlQ2+tR}Xy`2Doa4FYo_o&seeYGN)T+NCs05Ws
z`28sjcc5G@7Yc=6qU3V9ySuyF+gp^!$H#|<hx_|`%v36sPN(?`6G6#jGWc=6`m@>W
z)6-MUwj{s4zCJiO*xugW+}!kdJU>K1SzljYUS3{WT5>oXHk-|Ew=XU(Vj>F*3$wGc
zb8~YuGc)+-=jUB6*V@`zEEcQTg39;z_Xh_D`}+ENdwV-OJHLp6(%s$N-rla)>)YDe
z)M|BWYb*a?Rz;)HVB$p4>2ySPb#-~YUfLi%f;7L$Wa{bZ`6>!Ze}DfsQH(}oOG^vc
z1VI=Y8X6fH85<k3TCL;b<KIQW9335<o}LbcLd9ZHnqS(Vt*tFu^ivd+y}iAoqoY6|
zFgZD?)oLkkb#?Xl_&6L6pPik><MGSO%VaW{NF>hB&m)mYG#X_DFE20B{OHp8R;OJ3
z&FAx_Qi%~W3xmNx{q+Cl=7tVGKR;J06&8{W!K^ybYm&>F?6R}7!#FqsGX*WOOB4lg
zgu}x_v)N4jzy@S0S}q&R*-uYT86U7|Mt=Hyb#*l{F#!(g51*B6Ns0ofAGCl#K;De{
z0S4Fu^Yn)=7jjTko^0@I{h$4>+bjBia&j^}JPd<5oz8dfKi?ND1kZJJbU@e8Mcp#q
z?1Ue7cXtN{2B7PWjSViHH>aw*5U%t4{ZKdJ^Z9D%z3vi4P7=b~)%++QF@ID0!+g2O
zxGS49U+@_W1}zo~_*_|8d3SumKNlAlQ&Usizizji8&(lKWP`a<$;rcjx5vNF8`<TJ
S1h56K4v+~~G!p+G#QXu`7;60h

diff --git a/autotests/read/tga/bwa.tga b/autotests/read/tga/bwa.tga
index c0b2ab8f1ed2ec3da02a9f070202c3022c6a9ff7..d02091afde29568b89b7e06df49c8293bbe50ff4 100644
GIT binary patch
literal 737
zcmZ9K+fBnT6o&tlRzmGdM#v*Cpp1~0B2_{VaTAXj!6PIsMMzu}i2>*c86hKN1dosr
z_>O}?kk)bho!ftGODj!JCi|r)pVIXIkY-AiD}9!B(h-Xq-|<O)#_ZHKs^<ia!BRFB
zP^nbK*H)T?OU#9`y$%a?YWW@rtgs$q8_bzhp1}-VKt}agdex6|b4rfH9prYZ60Aj|
zZpQ31OlAIuED6a75MegD@QtS2v<{4^)L(fC(yX5q4Lf2y1K|`O$N_7<Hz8x0N_+XG
zg#`UICCs@nU5)w#nr@{x+cg)k8kH}BnBD<a5#T`Ywo?V=a^&{W#|Q1TDT#=jAz809
zq8xpu6d4iqEP9aCM#NTuJib{(bbt)={P9Zh8m9u$s|FpYnydIlE&I#i1no3v?byXA
z@Urxwov>qcX#E8rA2NB%_KRxs0Qm_esOEH?9Yq%rr8yNtIf&#^&JE!G8ZRo>H9oi3
TckBDj&F1Rz^x=GSu|Crmh=Y<U

literal 4114
zcmeI!O-qzf6u|LGGfSm1$P`?Z&AL8-i$aTR+sY5n!i^}@B8(tJ1*1T4T_{Y7P~bLl
z;np^l3r%n*_?D^Is~Y0}57&*%2!@=6bmYgK=Xu6CbI*O7Or|Ka7nd{qW%sWBx5uUe
zC+JBrZ2u+vztcF6b2xhd-*X8ys7~r=uj5L(zDVo)R0Xe3Azzr==l9TsPIMITnESoR
z;Vp(Sgi(yA_BHKGbfX6Yc!itD_Z>>Oe*<Iqh7~MgArJ4bVG~>UjbHox<oXA`CSLo#
z7qA}t<FNTR_yBXSV+Nlvf%o{3uBT|{l1W-?)qs5cKTQ1{A9MY|7d*fn)Z<!eZ_zrI
zZD_?^Ttz7gMG+6qpc2-o(EQ8tYy{Taem9{EC*fz<T2FITB=*@p9z{6sb8t+}e;ekD
z3fGBq+xg`fTjzu7%Htyq$EFL;ZRb}ztaDU2FP>rvu0{6)??puwi3Z_%b_|}wIU5zO
zqmS6ZHe3sSr>LkU(L4Nw`A6Y75EZUJ_cHTa18Y%-sBo<N;QIFrc!S9Po8NQ9GiU)1
z5xM?6@2$V*&u28kJvS=M@0|DinME@q_doYv*T4B)|NXdtsBr)7#do*|4Z$@L74Ef9
zu#8naL*)Kv{zsUH^WWczk^6r+`R-#n@wNA&qL@Tkv?RXvUSychJ}WwRWIvB>u3cTU
BfVltw

diff --git a/src/imageformats/tga.cpp b/src/imageformats/tga.cpp
index ccb08c2..b1193e6 100644
--- a/src/imageformats/tga.cpp
+++ b/src/imageformats/tga.cpp
@@ -174,15 +174,21 @@ static QImage::Format imageFormat(const TgaHeader &head)
 {
     auto format = QImage::Format_Invalid;
     if (IsSupported(head)) {
+        TgaHeaderInfo info(head);
+
         // Bits 0-3 are the numbers of alpha bits (can be zero!)
         const int numAlphaBits = head.flags & 0xf;
-        // However alpha exists only in the 32 bit format.
-        if ((head.pixel_size == 32) && (head.flags & 0xf)) {
+        // However alpha should exists only in the 32 bit format.
+        if ((head.pixel_size == 32) && (numAlphaBits)) {
             if (numAlphaBits <= 8) {
                 format = QImage::Format_ARGB32;
             }
-        }
-        else {
+        // Anyway, GIMP also saves gray images with alpha in TGA format
+        } else if((info.grey) && (head.pixel_size == 16) && (numAlphaBits)) {
+            if (numAlphaBits == 8) {
+                format = QImage::Format_ARGB32;
+            }
+        } else {
             format = QImage::Format_RGB32;
         }
     }
@@ -348,8 +354,7 @@ static bool LoadTGA(QDataStream &s, const TgaHeader &tga, QImage &img)
     uchar *src = image;
 
     for (int y = y_start; y != y_end; y += y_step) {
-        QRgb *scanline = (QRgb *)img.scanLine(y);
-
+        auto scanline = reinterpret_cast<QRgb *>(img.scanLine(y));
         if (info.pal) {
             // Paletted.
             for (int x = 0; x < tga.width; x++) {
@@ -359,8 +364,14 @@ static bool LoadTGA(QDataStream &s, const TgaHeader &tga, QImage &img)
         } else if (info.grey) {
             // Greyscale.
             for (int x = 0; x < tga.width; x++) {
-                scanline[x] = qRgb(*src, *src, *src);
-                src++;
+                if (tga.pixel_size == 16) {
+                    scanline[x] = qRgba(*src, *src, *src, *(src + 1));
+                    src += 2;
+                }
+                else {
+                    scanline[x] = qRgb(*src, *src, *src);
+                    src++;
+                }
             }
         } else {
             // True Color.