[LyX/master] Better PNG detection in guessFormatFromContents

[Yuriy Skalko]

commit 43477730a48ca809d260edbeae26e478bbf1871e
Author: Yuriy Skalko <yuriy.skalko at gmail.com>
Date:   Wed Nov 25 02:12:04 2020 +0200

    Better PNG detection in guessFormatFromContents
---
 src/Format.cpp |    7 ++++---
 1 files changed, 4 insertions(+), 3 deletions(-)

diff --git a/src/Format.cpp b/src/Format.cpp
index 6a3d49c..62c09d0 100644
--- a/src/Format.cpp
+++ b/src/Format.cpp
@@ -255,8 +255,12 @@ string guessFormatFromContents(FileName const & fn)
 			} else if (stamp == "\377\330") {
 				format =  "jpg";
 
+			} else if (prefixIs(str, "\x89PNG")) {
+				format =  "png";
+
 			} else if (stamp == "\001\332") {
 				format =  "sgi";
+
 			} else if (prefixIs(str, binEPSStamp)) {
 				format =  "eps";
 
@@ -319,9 +323,6 @@ string guessFormatFromContents(FileName const & fn)
 		else if (contains(str, " EMF"))
 			format = "emf";
 
-		else if (contains(str, "PNG"))
-			format = "png";
-
 		else if (contains(str, "%!PS-Adobe")) {
 			// eps or ps
 			ifs >> str;