Azure pipelines: no artifact upload/download from forks

azure-pipelines.yml

@@ -10,6 +10,7 @@ jobs:
       pathtoPublish: '$(System.DefaultWorkingDirectory)/distfiles.zip'
       artifactName: distfiles
     displayName: 'Upload extra distribution files'
+    condition: eq(variables['System.PullRequest.IsFork'], 'False')
 - job: Windows
   pool:
     vmImage: vs2017-win2016
@@ -38,6 +39,7 @@ jobs:
     inputs:
       artifactName: distfiles
       downloadPath: $(System.DefaultWorkingDirectory)
+    condition: eq(variables['System.PullRequest.IsFork'], 'False')
   - script: azure-pipelines/build-windows.bat $(wordsize) $(tool)
     displayName: 'Build, test, generate binary distributions'
   - task: PublishBuildArtifacts@1
@@ -45,6 +47,7 @@ jobs:
       pathtoPublish: '$(System.DefaultWorkingDirectory)/installers'
       artifactName: installers
     displayName: 'Upload binary distributions'
+    condition: eq(variables['System.PullRequest.IsFork'], 'False')
   dependsOn: Linux
   condition: succeeded()
 - job: macOS
@@ -56,6 +59,7 @@ jobs:
     inputs:
       artifactName: distfiles
       downloadPath: $(System.DefaultWorkingDirectory)
+    condition: eq(variables['System.PullRequest.IsFork'], 'False')
   - script: azure-pipelines/build-mac
     displayName: 'Mac build and test'
   dependsOn: Linux

azure-pipelines/build-mac

@@ -7,7 +7,9 @@ cd jpeg-9c
 make
 sudo make install
 cd ..
-unzip distfiles/distfiles.zip
+if [ -f distfiles/distfiles.zip ]; then
+    unzip distfiles/distfiles.zip
+fi
 ./configure --enable-werror --enable-show-failed-test-output
 make -j$(nproc)
 make -k check

azure-pipelines/build-windows

@@ -17,7 +17,9 @@ if [[ $tool == mingw ]]; then
 elif [[ $tool == msvc ]]; then
     cl
 fi
-unzip distfiles/distfiles.zip
+if [ -f distfiles/distfiles.zip ]; then
+    unzip distfiles/distfiles.zip
+fi
 curl -L https://downloads.sourceforge.net/project/qpdf/external-libs/2017-08-21/qpdf-external-libs-bin.zip -o qpdf-external-libs-bin.zip
 unzip qpdf-external-libs-bin.zip
 cwd=`pwd`