fix for crash caused by invalid active material index while editing text.

also added some better error checking in object_remove_material_slot() so it will print an error rather then crashing if this case ever happens again.

2 files changed, 14 insertions, 7 deletions

diff --git a/source/blender/blenkernel/intern/font.c b/source/blender/blenkernel/intern/font.c
index 4c8d0cf998d..9c01b35b91a 100644
--- a/source/blender/blenkernel/intern/font.c
+++ b/source/blender/blenkernel/intern/font.c
@@ -546,7 +546,7 @@ static void buildchar(Main *bmain, Curve *cu, unsigned long character, CharInfo
 			nu2->knotsu = nu2->knotsv = NULL;
 			nu2->flag= CU_SMOOTH;
 			nu2->charidx = charidx;
-			if (info->mat_nr) {
+			if (info->mat_nr > 0) {
 				nu2->mat_nr= info->mat_nr-1;
 			}
 			else {
diff --git a/source/blender/blenkernel/intern/material.c b/source/blender/blenkernel/intern/material.c
index ed9be989dbd..ebd05ab9bf8 100644
--- a/source/blender/blenkernel/intern/material.c
+++ b/source/blender/blenkernel/intern/material.c
@@ -1105,8 +1105,17 @@ int object_remove_material_slot(Object *ob)
 	short *totcolp;
 	short a, actcol;
 	
-	if(ob==NULL || ob->totcol==0) return FALSE;
-	
+	if (ob==NULL || ob->totcol==0) {
+		return FALSE;
+	}
+
+	/* this should never happen and used to crash */
+	if (ob->actcol <= 0) {
+		printf("%s: invalid material index %d, report a bug!\n", __func__, ob->actcol);
+		BLI_assert(0);
+		return FALSE;
+	}
+
 	/* take a mesh/curve/mball as starting point, remove 1 index,
 	 * AND with all objects that share the ob->data
 	 * 
@@ -1119,10 +1128,8 @@ int object_remove_material_slot(Object *ob)
 	if(*matarar==NULL) return FALSE;
 
 	/* we delete the actcol */
-	if(ob->totcol) {
-		mao= (*matarar)[ob->actcol-1];
-		if(mao) mao->id.us--;
-	}
+	mao= (*matarar)[ob->actcol-1];
+	if(mao) mao->id.us--;
 	
 	for(a=ob->actcol; a<ob->totcol; a++)
 		(*matarar)[a-1]= (*matarar)[a];